I have a light switch in the laundry room that has two white wires, one black wire. It had a problem with the switch so I decided to replace it. I bought a single pole switch, with 2 screws, and put the two white wires on one screw, the black on the other. The light stayed on and wouldn't switch off. So I bought another switch that has three screws, just like the old one. But I couldn't remember which wires went on which side. So I put the two white wires on the two top screws, the black on the bottom - no current. I switched the two white wires, but had them still both at the top with the black on the bottom screw - no current. I don't want to short circuit anything, but would the right answer be to have the black wire by itself on the top screw on the left, and the two white wires on the screws on the right, top and bottom?