I have been following this with great interest as I have installed three X10 switches. At each location the original switch was wired differently.

#1 was in a box with another switch. Each switch controlled a different light. The original switch had two wires connected. I hooked up the X10 with no trouble and the light works fine.

#2 was in a box with two other switches, each controlling a seperate light. The replaced switch had one black wire to the top post of the original remote-I put the blue wire of the X10 to this wire.

There was a black wire plugged into the bottom of the original switch, and another black wire with about 1/2 inch stripped away and the bare portion looped around the bottom screw, which I assume connects to the same place in the switch as the bottom plug in receptecle. one of these connected to the bottom screw of the next switch in the box.

I tied both of these together and attached the black wire of the X10 to these wires.

#3 was just as #2, but as it was in a box with three other switches, so it had three black wires attached to the bottom of the original switch. I hooked up the X10 the same as in #2.

All work fine, but do I have a shock hazard? I think they are hooked up just as the originals.