Attempted to install a TPLink Kasa 3way switch in asingle gang box. spent hours yesterday replacing wire into this box to add a neutral. missed it by that much, switch sticking out from wall by about 1/4 inch This is now electrically functional but I can't get this sucker all the way in because the box is kinda narrow & shallow, and there are 3 wire nuts behind. I suspect all boxes will be that small - do I give up on this brand of smart switches?

(in a different location where I had a 4 gang box and I only had one of these big boys go in I was able to tuck the wiring nuts behind the neighboring switches)

I'll measure the depth of the wall to see if there's a point in getting a deeper box but if I need to pull that with every outlet I might give up on the project or only do it as I'm about to paint a room.

  • 5
    The boxes do come in different widths and depth. Possible that box is small because it is used for a switch. Walls should have about 4 inch depth to them(drywall+stud). Probably do need to change that box or go back since you can't leave it hanging like that.
    – crip659
    Jan 2, 2022 at 16:39

2 Answers 2


This is a common problem. I had a similar problem simply replacing a ~ 60-year-old 2-wire duplex receptacle with a new (but nothing fancy, not GFCI) 3-wire grounded duplex receptacle. The solution: A bigger box.

In my case it was easy because the wall was open. With a finished wall it isn't nearly as easy, but not impossible. Standard walls in the US give you 4" - 3-1/2" for a 2x4 + 1/2" drywall, which is plenty of space to work with. The downloads from TP-Link don't list dimensions. Home Depot shows 1.77" deep x 3.35" wide x 5.04" high. That actually sounds a bit large - width and height normally ~ 2" x 4". But if 1.77" depth is correct, there should be no problem with a 3" box, and 3-1/2" are readily available:

deep box

  • I think most of my walls are with 2x3 studs ¯_(ツ)_/¯
    – nhed
    Jan 2, 2022 at 17:08
  • 2x3? That is unusual, but not impossible. 3" = 2-1/2" + 1/2" drywall = 3". If that is correct, you are limited to a 3" box. Which still should be enough. Jan 2, 2022 at 17:15
  • 1
    so went and actually measured - yeah while most of my walls (at least in the unfinished parts) are clearly 2x3s, this specific wall was along the primary beam and maybe considered a load bearing or whatever and measured the possible box depth to be larger than 4". However I managed to use flat push-in connectors instead of the wire nuts and with some careful wire arrangement plus pushing and shoving I managed to get it in.
    – nhed
    Jan 3, 2022 at 16:46

One thing you can try is an "extension junction box". For a finished-wall area like this, you want a fairly handsome one, such as a "Legrand Wiremold Surface Conduit Starter Box". They come in 1" or 2" tall, and you can see if the hole in the back of the 1" one will clear the KASA switch.

They are made for being launch points for surface conduits, but you're not obliged to attach any conduits.

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