Originally Posted by
Brian W.
Make sure that the black and red wires of the switch aren't backwards.Power from the circuit breaker should be connected to the black wire of the switch, and the lights should be connected to the red wire of the switch.Is this connected to a permanently installed set of lights, or is it wired to a receptacle that have the Christmas lights plugged into it?If it is wired to a receptacle, try plugging a standard incandescent/halogen lamp into the receptacle instead of the Christmas lights, and see if the lamp reacts properly to the Caseta switch.