Hi yall -- Thanks for helping me understand this problem. With big apologies in advance for my poor understanding and use of proper language here.

We have a large rectangular mirror centered on the wall above a single sink set into a vanity of sorts (old sideboard). Trouble is there are two -- what do I call them? -- recessed tins (recessed into the wall) with wires capped off in them in the wall above the mirror. Basically, this is a junction box perhaps? I mean, wires come together here and go out elsewhere, so I'm thinking "junction box"...?

Whatever the right word for these is (they're circular, not a "box"), they're clearly designed to be covered up by a bathroom light wallplate. However they're not centered above the mirror.

Please help me to understand my options.

1. Legally, I think we're not really supposed to plaster one of the "tins" over; I think we're supposed to put an (ugly) plate there if we don't hook it up to a light -- is this correct (I know, probably jurisdictional, but is it plausible at least)? Our inspector's gone; how stupid would it be to just plaster one of these (unused and likely unusable) holes over anyway? Is this a real safety concern or something one could get away with doing?

2. I see some lighting companies sell bathroom lights specifically with longer wallplates -- could one of these work using just the one "tin" that is offset left of center about 6"? I'd need a wallplate at least 18" or so I think to center above the mirror, and then the power source would be behind the wallplate off to the left -- is this doable? That is, hook-up-able (potentially, or are these things designed to hook up symmetrically around a power source)?

3. Can I mount a track light on a wall like this, perhaps across both "tins"/power supplies/power source (sorry, I haven't got the right language again)? Could this obviate the need to cover up one "tin"? That is, could a track light, presuming it is OK to mount on a wall, be installed using two power sources like this? Or ... maybe if all that's needed is a plate for the "tin", a track light could essentially just cover up the "tin" the way a plate would so it wouldn't matter whether the second power source were hooked in?

Thanks for taking a stab at these questions. I know my language is lame and my understanding worse. Any ideas anyone might have of how to deal with this I'd really appreciate.