I don't think your problem is noise - X10 signals are sent something like A1 and then A-OFF (or ON, or DIM, or whatever) with each signal being a 12 to 20 bit (I forget exactly) binary code which occurs at the zero crossing point of the sine wave of the electrical power - so, if I have this right, your chance of off having random noise send a X10 signal is less than winning the lottery every day for a month.

Noise would have the opposite effect - it would garble an X10 signal.

If the above is correct, then it follows that a X10 transmitter, either internal or external to the house, is sending the signals. To determine whether a neighbor on the same transformer is sending the signal or whether one of your devices is farkled (a highly technical computer term), you can turn on the lights controlled by X10 and then unplug all of your transmitters.

Transmitters include universal modules, mini and maxi timers, transceivers, Switchlinc switches, smart controllers, and possibly something else I can't think of at this hour.

If after doing this, you still have a problem, then I would conclude that the source of the trouble is outside your house. The good news is that there are two solutions: (1) find the neigbour on the same transformer and agree which codes each of you will use, or (2) install a signal blocker. These devices are made both by X10 Powerhouse and ACT - my guess, and that is all it is, is that the ACT unit would be better - and that is why I buy things like this from people like Robert - even if his prices are not the absolute lowest in the known world, and I think they are pretty good, his knowledge and experience can save one a lot of time, money, and frustration.

I believe the signal blockers also act as a signal bridge.

The bad news is that these devices require the neutral wire to pass through them after the electric meter but before the electric panel, so unless you are very very comfortable with this kind of work, it is a job for a qualified electrician.

Now, in the other case, where unplugging all your transmitters does solve the problem, add them back one at a time until you find the one that is the culprit and replace it. This is a slow and tedious, especially with an intermittent problem and an unhappy S.O. but at least the solution is not expensive in terms of parts and outside labor.

Good Luck, Jim.

The Law of Inanimate Objects: They either don't work, break down, or get lost.