The switch is a Combination Single Pole/3-Way. There is a light in the bathroom and one outside in the patio. I want to have them function independently but isn't happening. I inherited the wiring, so even with reading all these notes online, I still can't make it work. First question is - can I set the house on fire or blow anything up by trial and error? Secondly, the box with the switch has three lines coming in in conduit from somewhere (red, yellow, and blue - I bought a meter so I know the red is the hot one) and two lines coming in in conduit from the box above the mirror (a black one and a blue one - black is hot). The box above the mirror where the light will go has two lines coming in in conduit from somewhere - a white and a black (the black is hot). The box also has two lines going out, a black and a blue, and, when the black one is connected to the other black wire in the box makes the black wire in the switch box hot. The blue wire goes to the switch box also. As for the switch, looking at it from front with "line" on right, red wire goes to upper right, black goes to lower right. Other side has yellow upper left, blue from light box to lower left, and blue from switch box to middle left. See pics. Can anyone tell what's wrong? Thanks.

Hey, folks. Thanks anyway but I've now got a couple of balky ceiling fan situations (can't tell negative from ground - brown, blue, yellow wires all capped weirdly; a mess), a garage door that gives me the finger every time I ask it to open or close, and a pool timer that I can swear I hear chuckling when I set the timer, so since I was planning to call an electrician for those projects, I'll just throw the light switch problem at him, too. Probably a good idea anyway since I didn't wait for advice on burning down the house, and fried one pigtail really good. I'll stick to my computers. If anyone feels compelled to answer my question, though, I'd love to hear it. By the way, there is only one circuit feeding the switch, so breaking off the brass tag on the switch wasn't/isn't necessary.

Hey there,

I generally recommend this guide to folks who have trouble determining wire colors. It's a straightforward guide to figure out what color means what - which is hot, which is ground, which is your remote wire, etc.

Let me know if this helps.