I would like to replace this old light switch with a newer one, but as all newer electrical items it has a grounding screw to be connected and there is no obvious ground connection available in the box.
This house was built in 1963 (Colorado, USA), and it has several 3-prong outlets around the house that look newer, but not on this wall.
My investigations in this box actually make me worried if any of our 3-prong outlets have proper ground, as I read that the standard socket checking devices could be fooled with ground-neutral connections?
Here's why I'm worried:
- In the switch box photo one can see 2 neutrals connected via wire nut
- In the back of the box (which is metal) one can see a blank wire looking like its intention is to "ground" the box? It is screwed to the box at the back.
- I confirmed that the neutrals and the box are electrically connected (does that equal a bootleg ground?)
Adding to the confusion is the cabling of the switch:
- one red going in above,
- two blacks at the bottom, both on the same screw (but this should be a 2-way switch)
Hypothesis regarding the last point: Half of the rooms in this house have fans installed, is the double-wired black maybe a provision in case one wants to install a fan in this room as well?
So, the new switch of course wants a hot, a neutral and a ground wire, what am I supposed to do?
For additional background I add a photo of the 2-prong socket that is on the same wall. It also has a blank copper wire connected to the back of the box (interestingly, in both cases the screw connection was rather weak, I tightened it, hope that wasn't a special technique in older houses for some reason?)
My background, in case you wonder what level of detail you can load your answer with: I'm a physicist with lab experience (so give me all your details! ;), but no formal education as electrician; meaning, I'm confident enough when I understand things, but also reasonable enough to concede to the professionals when it just gets too complicated.