I am trying to wire a single-pole light switch and I have three cables coming into the box (3 black, 3 white, and 3 copper wires). The copper ground wires are bound together but I am not sure how to attach the black & white wires. It appears that one of the cables comes from underneath the box from a nearby receptacle. The other two cables go out the top of the box.
Originally asked by Thomas on Stack Exchange (diy) (CC BY-SA 4.0).
