My house was built ~3 years ago and i am trying to add some smart switches. I see that nearly all require a neutral wire. When i pull apart any of my switch boxes i see that a neutral wire is not connected to the switch, but in every junction box there is a bundle of white wires capped off in the back.

Would these be the neutral wires? and is it normal for traditional switches not to be connected to a neutral?

Picture of a switch box

1 Answer 1


Yes, and yes.

If properly wired (and this is always a potential issue), neutral wires are white. Hot wires are black, red, sometimes blue or other colors except white and green (which is reserved for ground).

Basic switches that have no electronic components simply make or break the hot wire. One side is hot and the other side is switched hot. Modern switches also have a ground, which is green or bare.

More complex switches, such as electronic dimmers, some lighted switches, wifi switches and others also need a neutral.

In the switch you have shown, the two hot contacts are attached to the black wires shown. If your switch has its own wires, the white wire is attached to the existing pair of white wires, and the proper sized wire nut then put back on. A white pigtail (a short length of the same gauge wire) should be connected to the neutral terminal of the switch if it doesn't have its own wire.

The two existing black wires should be attached to the hot terminals on your new switch. Also attach the ground wire to your switch, either directly to the ground terminal or to the ground wire.

If your switch needs a specific connection to the hot wire (also called line), you will have to test to see which of the black wires is hot and which is switched. If so, ask and we will explain how to test.

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