My grandparents had their two garage door openers and doors
replaced. The original receptacle is in the photo below. A 14-gauge
extension cord used to feed the other
one. The installer (from Sears) did away with that. Here's how he did
it: (Western PA)
Original handy-box with original 12/2NM (the white one), and the
Wire routed under heating duct and I-Beam. Original cable heading
towards panel. This is a dedicated circuit for the openers, I believe.
New box and recept. Yes, that's an old-work steel box that's been
surface mounted. The small wire is the remote switch for the opener.
Uninsulated staples are allowed around here, BTW. The local inspector
and my father are friends at a local gun club. Was this inspected? NO!