I've replaced some switches inside of a box before, but never replaced the full box, so I am bit stumped on how to actually feed the wires into this Carlon B117RSW Old Work Shallow Outlet Box.

Since I've moved into my house, there have been a few outlets that were off, crooked, etc. I found one was out and when I went to adjust it, I found they had used a traditional retrofit box, but it was making contact with foam surrounding a waste water pipe (ugh). I bought this shallow retrofit box so that it wouldn't rub up against the pipe and I could get it flush to the wall. I figured the sidecar would provide a bit more space just to work with even if not needed at the end.

After searching the web and manufacturer's website, I really only found brochures - no schematic/instructions, etc. I'm stuck. Here is a photo:

photo of back of retrofit box

In order to get the romex into this new box, what do I do? I don't see what bends and it's not clear if there is something I should punch out. I will be using the same outlet and wiring config (only one bundle comes into this box), so this is really the only hard part. I feel like there must be some obvious thing to do, but nothing seems flexible to bend or clear to break. Do I just break through the center of the V?


Maybe this one just had more residual plastic between the slots then most? Screwdriver wasn't enough, really had to cut away the material between, but still flexes closed at the end:

photo halfway through removing plastic

  • Force the cable (sheathing intact) into the middle of the V. Does it spread the leaves apart? Only after the intact cable is forced in do you strip the sheathing exposing the individual wires. Jul 10, 2021 at 19:37
  • I would be reusing the wires already in the box. am I supposed to cut those back and then restrip when replacing the box?
    – HelpEric
    Jul 10, 2021 at 20:10

1 Answer 1


Take your screwdriver and separate the two tabs just barely so your cable can be shoved in there. The ribbed edges will hold the cable in place. Make sure the cable is installed far enough so at least 1/4" of total insulation is in the box.

  • In these boxes with a narrow opening I have always had to push the cable far enough through the box so that the location where I am going to cut the sheathing is out of the box. Then I cut the sheath, pull it off, then push the cable back through the box so that there is about 1/2" of sheath inside. All this is done with the box in hand, only then is the box pushed in place in the hole in the wall, and secured. Jul 10, 2021 at 19:57
  • @jack to clarify: "separate the two tabs" you mean in the center of the "V"? e.g. they should spread if I put a screwdriver in there and push/wiggle? it should still try to come together after breaking, somewhat clamping?
    – HelpEric
    Jul 10, 2021 at 20:09
  • @JimStewart LOL ... I did it the same way... Also use to mark the sheathing, remove it and then push the cable into the box...
    – JACK
    Jul 10, 2021 at 20:11
  • @HelpEric Exactly, they need to come together. Different boxes have them molded differently so sometimes they need a little "twist".... just enough to barely separate them at the "Y"
    – JACK
    Jul 10, 2021 at 20:15
  • 2
    Also note that you must cut the sheath and position the cable so that when the box is in place in the wall at least 6 inches of each wire can be extended into the room past the interior wall surface. To the inexperienced person this seems like a waste of wire, but it greatly facilitates the manipulations required to connect receptacles. It also allows large enough looping of the wire to more easily push the receptacle into place. Jul 10, 2021 at 21:27

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