Random on/off for ONLY plug in modules

[ctviggen1]

I have an issue where ONLY (as far as I can tell) plug in modules come on or off or do not turn off.  For instance, my daughter's lamp turned on last night.  A lamp we have in our foyer turned on late at night one day.  Our towel heater randomly comes on. 

All of these are either on/off or dimmer/lamp plug in modules.  As far as I can tell, no in-wall on/off or dimmer switches do this. 

I have a large house but also an extensive Insteon system. All the switches on the basement and second floors are Insteon, for instance. They are all dual-mode.  The only remaining standard lights are on the first floor, and I have the switches to replace these, but not the time to do so.

I have ordered some outlet-type (in wall) modules to replace some of these. However, I cannot do this for all of them.  In my daughter's room, I have multiple plug in modules so that she can control "fairy lights" and a lamp.  In another room, I have a fish tank light, and two lamps being controlled, all from the same single outlet. I have replaced the PLM with the latest model. I have filters on (basically) everything that should have one. 

Why are my issues only plug in modules?  How do I debug these?

[Brian H]

Are the modules in question the presently sold Dual Band Modules or the older power line only 2456S or 2456D Modules?

On but not off can be the load is making noise. So it can be turned On but the noise keeps it from going back off. Can you unplug the load on the one not going off and see if it then acts better?

Have you used the built in communications tests in the modules if they are the Dual Band models?

If you have the LED set to blink on power line traffic. Are any of them blinking when no Insteon commands are being sent?