You folks are right on! It is a 110v junction box. There are two circuits radiating from the box, one powers the univolt.
It looked like it was mounted to the interior skin as the cover is square and about an inch deep. I think that is why I was confused.
I guessed the black "romax" two conductor plus ground orphan wire at the circuit breaker box might have been for a future AC. I also have an orphan wire located in the fridge cabinet. I thought it might be the same wire. But the fridge cabinet wire is a black romax with just two conductors in it, no ground. Most of my 110v circuits are in black "romax", and most of my 12v
circuits are in white "romax". So I don't know where the orphan 110v wire goes. And I tested the one fridge cabinet wire for 12v
and nothing. The wire is not energized.
Too darn cold around here!