As a result of exchanging our surface mount medicine cabinet and regular mirror between bathrooms, I'm moving the light bars that were mounted over them. When I took them down, I noticed that the there is not back to them, that they were mounted so that they were open to the painted sheetrock wall. I believe this is a violation of the NEC. Am I wrong?

There is a 4" round box in the wall, and the fixture wires were run into this box where they are attached to the NM-B wires via wire nuts. A bracket attached to the box by screws contains a threaded post that the light bar frame fits over and is secured by a nut, as is the case for many fixtures. So far, so good. What bothers me is that the round box is open to the much larger inside of the fixture, so that the fixture wires run along the drywall. The light bar frame is a open-backed box about 13"x4"x2". Arms that hold light sockets are screwed into holes at either end. A cross section of it mounted against the wall looks like
this:
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The problem is that the left vertical line is the wall. I would think there should be a back to this fixture. I went to Home Depot and looked at the similar ones they had on display, and they had backs, but I'm uncertain if that is just for display purposes.

These fixtures were installed 13 years ago in a remodel. I have since found a number of illegal things our electricians did, for example installing fixtures that require NM-B (because of their heat output) directly to older NM cable, wiring the GEC and neutrals together (apparently to fool the inspectors), etc. One was wearing an ankle monitor during the project, which should have been a big clue to us as to their character. (They were sub contractors, and we didn't hire them directly.)

So my question is: Do these fixtures need a back?

Stratmando

The were designed to have a back, and have wiring enclosed, It was "Rigged",
I see licensed people do some of this stupid stuff too. Some can't figure out or don't have correct tools.
It IS a code violation.