Switch – Grouding on a incandescent 120 V dimmer

dimmer-switch

The light dimmer of my chandelier broke recently so I went buy a new one (incandescent 120 V 600W). The one that broke was fairly old (sticker on the dimmer mentions 1987).

Since I'm pretty novice about electrical stuff I took a few picture before installing the new one.

As you can see it is sharing the wallbox with a light switch and there was two black wires connected in the wall. The dimmer I bought has a third green wire for grounding. What should I do with this third wire ? For now I capped it and it's working fine but I'm concerned about safety. Shouldn't this be connected somehow ? If so where ? I'm not sure that the wall box itself is grounded.

Thanks in advance for your help.

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Best Answer

Since there doesn't appear to be any grounding conductors in the box, and the box appears to be plastic. You've done all you can do, aside from installing a nonmetallic cover plate.

This answer might also be helpful.

If you're concerned about it, consider that it's been operating without a ground since the switch was originally installed. If you're really concerned, you could install a GFCI breaker to protect the circuit. If you're really really concerned about it, you could install an equipment grounding conductor from the panel to the switch.