A CEE News reader discovered these electrical branch circuits, which were installed in plumbing pipes in a Midwest trailer park. They were used to supply various receptacle outlets on posts in various locations.

The use of plumbing materials is not recognized as a wiring method in accordance with many sections in the 1999 NEC, especially Section 110-8, where only suitable wiring methods are included in the Code. The recognized methods of wiring shall be permitted to be installed in any type of building or occupancy, except as otherwise provided in the Code. See also Section 110-3(b) and Article 347.

We will never understand how they got the wire into the pipes. However, the venting does seem to be correct.