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Trying to change a light switch in my house. I am Chicago within city limits.

House is pretty old...it was “gut rehabbed” in the 80s but that doesn’t really mean anything. Actual building been here since 50s/60s.

Anyway, there doesn’t appear to be any ground wire. So what do I do with the ground wire I have on the switch I’ve bought. And is this lack of ground a huge issue that I need to get resolved? I’ve lived here over a year and get occasional shock in basement (but only during winter so put this down to static given it’s the dryest part of house). I attached some pictures to show what I’m dealing with.


This work is of an age when it should've been built grounded.

This appears to use the conduit wiring method. And this is metal conduit, probably EMT, so the metal conduit provides the grounding path. This connection is in fact grounded.

That, by itself, does not bring ground to the device. However, since this is a switch, it is automatically grounded via the metal mounting screws.

That is not allowed for receptacles (sockets). For that, you need to run a wire from the metal box. The best way is to find a hole in the back of the box which is tapped #10-32, and is made for a ground wire. They make special green #10-32 ground screws with optional pigtails, though any 10-32 screw will do. Don't use a sheetmetal screw unless it's tapped 10-32.

  • Thank you @harper. That is a relief! – Andrew Smith Mar 10 '19 at 20:34
  • Do outlets with a self-grounding tab not meet the requirement? – JPhi1618 Mar 11 '19 at 15:35
  • @JPhi1618 Depends how well it makes contact. Relevant thing is the screw thread alone is not a valid ground path for receptacles... what's required is hard, flush metal-metal contact with the box metal without paint debris, rust, or those little plastic squares that capture the screws getting in the way. If the tab accomplishes that, good enough. – Harper - Reinstate Monica Mar 11 '19 at 22:46

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