Electrician Allen Gallant surprised his three young sons with his debut on the hit TV show, “This Old House.”

“I was sitting there and my three sons saw me on TV,” said Gallant, owner of Gallant Electric, Lexington, Mass. “They laughed and said, ‘Dad, that's you.’ It was absolutely hilarious. You should have seen us the first time I was on the show. We looked like a bunch of losers eating our bowl of popcorn.”

“This Old House,” America's longest-running home improvement show, is now celebrating its 23rd season on PBS. The show selects two projects each season — one in or around Boston and the other in a town with a mild climate where outdoor work can be undertaken during the winter months. Bruce Irving, senior producer for “This Old House,” said Gallant has been asked to serve as the electrician on many of the New England projects because he gets the job done right and has a natural onscreen presence.

“His workmanship is terrific, and it's matched by a sparkling personality and an amazing haircut,” Irving said. “It looks like he stuck a fork in an outlet and his hair never really sat down again.”

Irving said Gallant and the other electricians on the show play a critical role in the renovation of the historic homes.

“They provide an absolutely essential and increasingly sophisticated system within these buildings, often dragging them from decades-old systems into the present,” Irving said. “On ‘This Old House,’ the standard operating procedure is to update the wiring because there's never a better time than when the house is all blown apart. It's also policy to ‘over-wire’ or at least leave chases and places in walls that you might want later on.”

On “This Old House,” the electricians have to preserve the history of the home while bringing it up to the modern electrical code.

“In the four projects I've done, and I've just started the fifth project, none of them had enough electrical work that was worth saving,” Gallant said. “The house is old and you are doing all this other work. It doesn't make a lot of sense not to rewire the last three or four rooms in the house. Cost wise, we're there and it's the time to do it. You're going to paint; you're going to paper. Let's do all the dusty work and get it over with.”

The electricians who work on “This Old House” are always confronted with two challenges — controlling dust and snaking wires.

“Dust drives the customers nuts and off the deep end,” he said. “People don't want to come home from work and have to clean up behind an electrician every day. Fine dust seeks its own level so it goes everywhere.”

It also takes a lot of labor to get wires from Point A to Point B in an old home, he said.

“If it's an old house, obviously they're not going to tear the walls and the ceiling down so I can wire without the walls and the ceiling,” Gallant said. “I have to do it while they're up.”

The most challenging fishing project for an electrician on “This Old House” was a Federal-style house dating from the late 1700s in Salem, Mass., Irving said.

“It was a timber-frame building that required some pretty fancy fishing and drilling to get around all the hidden timbers that always seem to be in just the wrong place and behind the most wicked horsehair plaster,” he said.

In nearly every project, the electricians demolish the existing wiring, which is often knob-and-tube, and completely rewire the home. On occasion, however, they'll find some valuable light fixtures that are worth saving.

“There's nothing good about old electrical with the exception of old electrical light fixtures,” Gallant said. “The antique wiring is no good, but if the fixtures are rewired, they are like gold. People spend like crazy. I had a couple pay $600 for a set of porcelain lights to go beside their vanity. They were trying to build a replica 1940s bathroom.”

Irving said General Contractor Tom Silva is looking for electricians who can not only rewire a house, but also feel relaxed in front of the camera and can develop a good rapport with the rest of the crew.

“Everyone gets along fantastic,” he said. “It's one of the filters through which everyone has passed. Not only are they an expert at what they do and their work is worth showing and celebrating, but they can also work in this three-ring circus of ‘This Old House’ projects.”

The show is looking for upbeat, roll-with-it, can-do tradesmen who can work with the homeowner, and also with the general contractor and the television crew, Irving said.

“I think that part of being the best of the best is not only your technical proficiency, but your ability to communicate and work with both colleagues and clients. If you're good at that, you're going to be good on camera, too. It all works nicely together. I think contracting is a communications business as much as it is a technical undertaking.”

Some electricians come alive under the lights while others calm up, Irving said.

“Electricians are just like everyone else,” he said. “I can't imagine how I would act if someone shoved a TV camera in my face. What it's really all about is getting these folks comfortable and explaining what they do every day, which is not always easy. There may be things that are obvious to them that they wouldn't even think of mentioning. We try to get them to break down what they're doing and explain it clearly by asking the right questions.”

The director and producer sit down with the electrician to talk about what he or she is working on, and then agree on the topic. The TV team, however, doesn't walk in with scripts, he said.

“We know the general topic of conversation, but we don't know the specific bits we're going to talk about until we're standing there,” Irving said. “I think the informality of it all puts people at ease. Before you know it, it's just turned into a conversation and they're just answering questions.”

The tradesmen who don't meet these expectations aren't invited back, he said.

“Those who don't show at the drop of a hat or those who don't complete when they say they're going to are never seen again,” Irving said. “It's like any general-contracting job.”

Tom Silva, the general contractor for “This Old House,” moves with the show around Boston. The crew often calls upon Gallant to rewire the local homes, but for projects in towns that are a considerable drive from Boston, such as Manchester, Mass., “This Old House” teams up with tradespeople in that location.

“We did a job last year that was so far away that we said, ‘Why don't we would we work with the best local talent we can find?’” Irving said. “Occasionally, if we're working in a town and there's a great electrician in the town, we'll sign up with him.”

“This Old House” also leaves New England to work in sunny locations such as Florida and California during the winter months.

“When the show leaves Boston, we're in the hands of whatever general contractor we're working with there,” he said. “In those cases, we'll come to town and ask around and say, ‘Who is the best builder?’ That's how we latch on to them. They bring their stable of people with them.”

Unlike many other television shows, “This Old House” does not take applicants for the starring roles. Tradesmen, such as electricians, are simply recommended by the homeowner, builder or general contractor. As the general contractor, Silva often discovers the tradesmen to work on the different projects.

“He's an honest-to-God general contractor working for the homeowner and he brings people to the job he thinks are up to it,” Irving said.

“This Old House” is a TV show, but first and foremost, the crew is sort of a family, Irving said.

“I'm not to say it's all nepotism, but we become aware of people in ways other than them throwing themselves at us,” he said. “If an electrical contractor heard that we were coming to their town to do a full-on project, he or she would be welcome to put him or herself forward to our general contractor.”

The electricians on the show do not work for free, and their contract is with the homeowner who is paying the bill, not “This Old House.”

“If they can find their way through to a nice brother-in-law's price, all the better, but mostly, we expect them to roll with the demands of the television show without passing any extra costs or overtime to the homeowner,” Irving said.

Electricians supply and charge for electrical equipment. For big-ticket items, such as a generator, subpanel or communications system, however, “This Old House” will ask a manufacturer to consider donating or discounting the product.

“Even though we can't say the name of it on the air, they are still willing to do it,” Irving said.

More of the historic homes are getting equipped with generators and home-networking systems, Irving said. Occasionally, “This Old House” will spring new technology on the tradespeople.

“Allen was forced to deal with some fiber-optic lighting on a project of ours, and it was a disaster,” he said. “Because the show wanted to feature something new and different, we said, ‘Guess what you're putting in, Allen?’ And he rolled with it. Working with it, we came to see over time that this particular technology is just not there yet.”

“This Old House” is now working on a Winchester, Mass., home that Irving describes as the “quintessential American house from the 1920s.” Gallant will work on the Winchester home full-time for six months. “It looks like we're going to totally rewire it because it's obviously old and tired,” he said. “It's a 2,900-sq-ft house in a prominent neighborhood in Winchester, Mass., right outside of Boston.”

Over the show's 23-year-history, dozens of electricians have made guest appearances on “This Old House.” Click here for profiles of “This Old House” electricians who have worked on a 1907 Craftsman-style bungalow in Santa Barbara, Calif.; a summer cottage in Nantucket, Mass.; and a Mediterranean Revival-style home in West Palm Beach, Fla.