enter image description hereI have 3 switches that power a light. The smart switch manufacturer I use everywhere else in my home (Kasa) does not make a 4-way switch kit.

What I've done for now is to remove the 4-way switch and install the Kasa 3-way kit at the other two locations and that works great (the 4-way switch is thankfully at a location nobody uses anyway).

To accomplish this I bundled the two red wires and then separately bundled the two black wires of the 4-way switch.

All good so far. Except now I had the bright idea to put a single-pole Kasa switch where the old 4-way was, and simply use Kasa automation to make this switch act as though it were part of the 4-way setup. I've done similar automation before (Kasa switch turning on lights that it is not connected to) and it generally works great.

Essentially this "dumb" single pole smart switch just needs constant power and wifi and it can participate in this automation. Therein lies the problem. I figured I would just connect the load/line wires to the red/red and black/black bundles, except this results in the new single pole switch only receiving power when one of the other (real) switches are in the ON position.

So then I thought maybe I just bundle all 4 (red/red/black/black) in one wire nut and connect the new single pole switch to that.

But that makes me nervous, so I haven't done it yet. Any guidance here as to whether that's safe and/or will work would be appreciated!

  • 1
    Is neutral available at that 4-way location (or, alternatively, a white-insulated conductor in NM cable that is currently being used as a line/hot)? Electric code (NEC) has required it for several years, but if your building is older, it might not have neutral available there. Photos of what's available in all 3 locations may be helpful.
    – Greg Hill
    Commented Nov 28, 2023 at 16:29
  • 1
    I'm no expert, but I'm not sure that you're ever guaranteed to have always on power anywhere on a multi-way circuit except maybe at the switch that power comes in to (that may or may not happen - you can have power to a fixture first...)
    – FreeMan
    Commented Nov 28, 2023 at 17:11
  • @GregHill I'll upload a photo now of the 4-way location, but all I'm seeing are the two black, two red, and one copper ground.
    – ricklane
    Commented Nov 28, 2023 at 19:21

1 Answer 1


Let's start by focusing on the goal. You want to install a Kasa remote which does not use any of the switching wires, since it communicates with the master via radio. However, it needs always-hot power and neutral to power itself. Is that correct?

The answer is to completely ignore the wires associated with this switch, and look at the other two switches. If they are an old school pre-2011 switch loop, then they are useless, but hopefully both aren't. If either one has an always-hot+neutral pair, then you simply power the remote switch off those two. It's fine if they're on a different circuit.

Note the pair must enter the box on the same cable. Do not take always-hot from one switch and neutral from the other switch.


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