Pop The Rocker Panel Off With A Screwdriver
How do I set the house and unit code on my Decorator-style wall switch?
Pop the rocker paddle off the X10 Decorator Switch using a flathead screwdriver; there is a small gap at the bottom of the rocker paddle. Set the House Code dial to the same letter (A thru P) that you set on your X10 controller(s). Set the Unit Code dial to an unused code (1 - 16) which can be controlled from any X10 controller. Replace the paddle.