I was adding lights in a basement closet and when I cut the ceiling open this is what I found.

It looks like previous owners didn’t bother protecting wires or moving boxes outside of the drywall when they did a remodel in 2000. I can lower the box down so it can be accessed once the drywall goes back up.

Obviously it Isn’t practical to tear out an entire finished basement ceiling to properly rewire and pipe the THNN. What would you do to make this situation safe that is practical?

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Update: I opened up the entire ceiling in the closet and sure enough the vertical drops are right there for the outlet and light switches above. Would it be possible to use an adapter to connect conduit to those vertical runs? I would use a new box obviously and would have access to that in the ceiling with a blank face plate. It is a closet so that plate won’t bother me. Would this be acceptable solution?

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  • 7
    I'm not sure that is THHN. They may have just shucked wires out of Romex. It looks like in a few places they needed more wires than come in Romex, so they just mix and matched. Total amateur hour though, open knockouts, no strain reliefs etc. Also I brightened up your picture a bit. Commented Aug 5, 2021 at 17:37
  • 10
    My concern here would be WHAT ELSE has been done improperly and is hidden from view? Clearly there was no permit pulled for this work or it would have been inspected and FAILED. I'd look for any other signs of this sort of work and open up all the walls if needed. Drywall is a LOT less expensive than a fire.
    – jwh20
    Commented Aug 5, 2021 at 18:25
  • It's hard to tell how many wires are entering and leaving the junction box. I wonder what this circuit is servicing. It might help if you make a basic circuit diagram, or just notes, on what this circuit looks like beyond this snapshot.
    – cr0
    Commented Aug 6, 2021 at 14:38
  • If this were my house I would start opening walls. Gradually and carefully, only enough to find all the work done in this manner and I would replace all of it. You say it isn't practical to open up the ceiling ... I think it is. It isn't practical to fix this without damaging some drywall. This is really bad.
    – jay613
    Commented Aug 6, 2021 at 18:39

2 Answers 2


By "feel safe" I think you probably meant "be safe." And I can't see how to make the installation safe other than putting in code-compliant wiring. How big of a job that is depends on some things you didn't mention, such as the size of the basement, length of wire runs, etc.

The photo you posted shows a junction box that was hidden, without a cover, without strain relief, and with a mess of electrical tape of unknown purpose. So it isn't just that THHN wire was run outside of conduit; there appear to be a multitude of safety issues. I wouldn't "feel safe" until I had followed any suspect runs of wiring and discovered any and all deficiencies.

Since the THHN was not run in a code-compliant way, I doubt it is stapled or otherwise secured inside the wall. This may allow you to use the THHN to pull new NM cable instead, which does not require conduit. Doing this may allow you to open less drywall.

I feel for your situation. I am not a professional and home renovations can be very stressful. I wish you the best!

  • 7
    It's far more practical to rip out the drywall on the ceiling (and walls, if need be) than to watch the place burn, or die inside it burning and not get to watch. Sometimes you buy a pile of prior problems, when buying houses. You need to adjust "practical" to consider what's important, not what's convenient.
    – Ecnerwal
    Commented Aug 5, 2021 at 18:00
  • 9
    In the very near term, swapping to AFCI or AFCI/GFCI combo breakers on as many circuits as possible would be a very good plan if any of your wiring looks like this nightmare.
    – Ecnerwal
    Commented Aug 5, 2021 at 18:07
  • 1
    @Ecnerwal Chances are they'll all trigger... nah, just joking. Commented Aug 6, 2021 at 5:30
  • 1
    Strain relief is provided by a NM cable clamp, shown here homedepot.com/p/… The purpose is to securely hold cables inside the box so that they cannot be accidentally pulled on and cause loose connections inside the box. A secondary purpose is to close up the knockouts on the box.
    – stmp945
    Commented Aug 6, 2021 at 15:12
  • 1
    @cr0 to add to stmp945 strain relief means that when someone pulls on the cable that force is dissipated onto a something strong, like the body of the cable where it is being clamped, as opposed to being applied to the other connection point, the wire nuts inside the junction box, which you don't want being tugged on because they could come lose.
    – Brad
    Commented Aug 6, 2021 at 15:17

A few years ago I moved into a house and discovered that one area of suspect wiring actually was a lot of wiring not up to code throughout the house. Not just knob and tube, also lack of ground wires and mismatching wire gage to breakers. This answer isn't about specifics to fix, more general based on my experience and the help of a great electrician:

  1. The help of a great electrician is invaluable. If cost makes this impractical, you need to prioritize what can be done as I said in part 4. I was lucky to find an electrician who was willing to get hands-on with the tricky things and was willing to inspect my DIY work on the easier labor (they knew that I had familiarity with electrical and am a careful person).

  2. You can rapidly make this safer by putting extra protection on the circuits, such as AFCI and GFCI breakers, as Ecnerwal said. We did this in my case and the more I learned about electricity, the better a move it seemed.

  3. Come up with the simplest method to make your use case safe, starting from what you have now. Often times we found that redoing shoddy work was a lot more work than just removing/disabling shoddy work and creating a safe setup from scratch. A good electrician can help problem solve here as they will be more familiar with what works and doesn't for routing wires, meeting different use cases, making shoddy work safe etc. For example, like stmp945 said, maybe you can tape NM wiring to one end of the THHN and pull the THHN through to get the circuit rewired without much trouble. Alternatively, you could see if there are safe parts of that or another circuit which you can safely extend to power this light you want.

  4. Inspect your panel to see if anything needs to be made safe there. From then on, prioritize circuits that are known to have problems (like what you found) and circuits that are more likely to create hazardous situations (like those servicing wet areas, outlets for electrical heating,or other high power use). I say that because there is only so much you can do at once (and again, by prioritizing AFCI+GFCI protection, you can at least reduce fire hazard fairly quickly).

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