I have a round junction box protruding from an exterior wall. It had a fixture on it with a circular cover, but I've replaced it with a fixture that has a rectangular box which I would guess is supposed to be tight to a wall (see photo).

The area where this is installed is covered, but there is free airflow into the junction box and I can see the wires if I poke my head back there.

Are there any risks to having this wiring exposed in this way?


  • 9
    The "risks" are probably low of something really bad happening, but it's cheap and easy to fix, and it looks janky as-is, which is reason enough. If enough dead bugs pile up in there, the carcasses could retain moisture and corrode the box and wiring. That protein can also attract rodents which could chew on the wiring.
    – dandavis
    Feb 12, 2021 at 16:13
  • 6
    It's not air exposure that's a problem. None of that hardware is airtight. It's a matter of damage protection and fire containment.
    – isherwood
    Feb 12, 2021 at 16:19
  • Agreed with the other comments; air itself isn't a problem (the box is filled with air anyway), but other stuff getting in or out could be.
    – Nate S.
    Feb 12, 2021 at 16:24
  • Is there a wall box the fixture sits on, or does a cable simply come out of the wall into the back of the fixture box? Feb 13, 2021 at 0:23

3 Answers 3


That needs to be closed up. Use a round to rectangle box adapter.

enter image description here

Image from amazon, no endorsement implied, it was just the first one to come up and I'm being lazy.

  • Thank you, this is very helpful
    – Justin
    Feb 12, 2021 at 16:56
  • That looks familiar diy.stackexchange.com/questions/215987/… Feb 12, 2021 at 17:54
  • That plate uses the mounting screws of a receptacle which are spaced at 3-9/32". The distance between the screws on an octagon box are 3.5". That's the wrong cover for the wrong box (because it's not recessed).
    – Mazura
    Feb 13, 2021 at 1:29

The fixture is (probably) properly mounted to the box, and that method is not likely a fire or water hazard at that location. But the problem is the fixture is intended to be mounted to a flat surface, and contact with the fixture could easily tear it off due to ease of something getting hooked behind it.

The simple solution is to trim some pieces of lumber and box-in the outlet box so the fixture has a flat surface to mount to.


The main problem is that it looks shoddy compared to the rest of the handywork, from that perspective. It could survive 100 years like that, especially if the wire is not thin copper strand and the humidity is not high.

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