I'm replacing a mailbox lamp for a friend. I'm getting 120V across the black and bare. I get no voltage across black and white. I'm assuming that the neutral is broken, probably underground. An electrician estimated $500 to dig a trench and replace the cable from house to mailbox. He couldn't advise me (for liability reasons) when I asked if black to bare would pose any safety hazards. So I'm researching for the answer. I was thinking that I would wire it that way, making sure that the breaker controlling it was GFI protected. The mailbox and lamp and post are all metal. I'm just not impressed with solar/LED arrangements.
Any advice? I appreciate any help.