Ground Wires Not Connected to Anything in Light Switch Box

Question

I'm trying to install a dimmer in place of a light switch in our bathroom. In opening the 3-gang light box, I see that none of the switches has a ground attached to it. The light box is plastic and since the house was built in 1997, I would have thought each of these switches would need a ground attached to it. In the back of the box there are other capped white wires (neutrals?) along with a capped bundle of copper ground wires. (See photos.) Since the light box is plastic, shouldn't these light switches (and my new dimmer) be grounded?

Answer 1

Light switches in plastic boxes should be grounded via a pigtail that goes from the bonded ground wires to the grounding screw on the switch. If you don't have that connection, you can add it yourself (just make sure the breaker is off and use a voltmeter to verify). Realistically, if you are using plastic switch plates, it doesn't make much difference, but I believe NEC requires it now and it's always better to follow the code.

If the box was metal, the pigtail would attach to a grounding screw on the box itself and that would effectively ground all of the switches in that box.

Edit: as long as you're in there, it would be a good idea to change all of the connections so they are connected to the screw terminals and not the backstab connectors. I can see in the second photo that one of the backstabs even has exposed copper, meaning either too much insulation was removed, or the wire was not pushed in far enough. This was done by a non-electrician, or a very lazy electrician.

Answer 2

They should be, in a plastic box, and probably code also.

Light switches are usually plastic are you can touch them and is less chance of shocking you, but still should be grounded.

The bare ground wires might also come close to the screws that are hot if not careful in placing wires back in the box, tape around switch screws can help.