I installed 3 smart switches on one side of our entry by connecting each to the white bundle of neutral wires at the back of the box. Pretty simple and they all work fine. There are 3 more switches I want to replace, but what should be the neutral wire bundle has 2 black wires. Do I have the necessary neutral wires for the smart switches?[![enter image description here][1]][1] the 3 way on the left connects with the 3 way I just replaced in the other box. I added a drawing to make things clearer. The 2 black wires in the white bundle lead in and out of the box and are from the cables that include the red wires bottom left and top right.

[1]: https://i.stack.imgur.com/cHEG1.jpg![enter image description here](https://i.stack.imgur.com/gpfPk.jpg)enter image description hereenter image description here

  • Wow -- that box is very messed up indeed from what I can see in there (two of the white wires in the suspect junction go into cables whose black wires connect to more than one switch and one of the black wires tied to those white wires goes into a /3 cable whose white and red wires are connected to one of the switches fed by the black wires corresponding to white wires in that junction) Oct 2, 2021 at 2:05
  • Neutral is the white wire not connected to any switch. And neutral is can be only one wire, make pigtails to connect few devices.
    – user263983
    Oct 2, 2021 at 13:37
  • Thanks. I added a drawing to make things clearer. The only white wires not connected to a switch are in the bundle with the 2 black wires. Oct 3, 2021 at 4:43

1 Answer 1


It's hard to believe there are no neutral wires in that box. It's possible they used black wires for neutrals but I doubt it. Most likely those are switch loops where they used white wires as hots. The best way to find out is to get a multimeter and measure that black/white bundle against ground. If you get 120v you know it's hot.

There are many smart dimmers that don't require a neutral wire. Although they are requiring it now for many devices. And the NEC now requires a neutral wire in switch boxes for this very reason.

  • I added a drawing to show where all of the wires go. I want to use Kasa switches so they can be grouped in the app. Oct 3, 2021 at 4:35
  • Do you own a multimeter or have access to one? You can get a very inexpensive one for about $15. It's a required tool if you want to do your own electrical installation and/or maintenance.
    – DrSparks
    Oct 3, 2021 at 20:17
  • I could not find my multimeter. I bought a new one, if I am using it right there does not seem to be any power to the neutral bundle with 2 black wires. I set the meter to 250v squiggle line and connected the black probe in the copper ground bundle of wires and the red probe to the black/white bundle. Nothing registers. There does not seem to be any power to those black wires in the white bundle. Oct 5, 2021 at 1:44

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