I installed a lighting fixture in the hall, running off an older fixture. It worked fine with the existing switches. Then I wanted to replace one of the two old switches (circa 1949) with a dimmer (lamps are dimmable LEDs).
When I took out the old switch, there were three colors of wire from the box: black, white, and red. The dimmer has two black and one green. I connected the dimmer wires to the box wires in the position they had been respectively on the old switch, but was unsure about the red/green connection. I did it, and the dimmer worked. But now when I flip the second old switch - identical to the one I replaced - it trips the breaker, and did so until the breaker wouldn't even power on.
So I removed the dimmer, and everything else on the breaker works fine - except the hall lights, which won't power on (I understand, I think, that there must be a switch connected to each outlet to close the loop in order for the lights to power).
Should I cap the red wire extending from the box, and just wire the green/ground from the new dimmer to the box?