Brian H's PDF shows what I wish the switch looked like, but it doesn't. I think there must have been a redesign somewhere along the way... or, it isn't an old XPS2.
Dave W... my switch has no LEDs. I'm making the assumption that power to the motor is 240v, but it could be 220v, and if so, an old version of an XPS3 if there is such a thing.
It's ok to be nosy when you're attempting to assist someone. My problem started a couple of weeks ago when we returned and found the pool running when it shouldn't be. As my wife and I pondered whether someone was using the pool why we were out of town, the pool suddenly shut off, and then a few seconds later, started back up. The timer (Intermatic T104R) was working as it should. It was about 112 degrees, so I got to thinking maybe I have a heat sensitive component. That's when I started down the road of trying to remember how X10 works. There shouldn't have been any house line noise, but it's possible there were surges as the a/c units came on and off.
My controller is an old Radio Shack 61-2677C. I noted that the "off" switch for the motor is not working, but the "all lights on/off" functions correctly. That controller sits in a kitchen window that does get a bit of heat, and it's old, so I've ordered a replacement (not Radio Shack) controller to see what happens.
Ever since that one episode, everything has worked great. My desire to pop that cover is simply to (1) learn how it works, and (2) perhaps change the channel as a debugging technique. Since it is working fine now, I'll shotgun the controller on general principals. I likely not change the channel now since things are working, but I'd like to figure out how to remove the rocker plate in case I really need to in the future. I just don't want to physically break it by applying force where I shouldn't.