I recently had an Insteon on/off module turn on without any user or program intervention. A few days later I experienced an all on event, where several of my older modules turned on.

I traced the problem back to the (failing) on/off module. I tried a factory reset / restore but the ISY had difficulty communicating with the module. I replaced the module, and all my problems went away.

The defective module was a hardware version 1.0 dated 2013

Since it also has a small switching supply chip and probably a cap with out good ERS properties. It may have had a failing power supply?

I have 6 on off modules and one still in the box. Where from the plastic case cracking time and are all in the to be recycled bin. As they where not safe when you unplugged them and the whole case came off and the powered up guts where all there to be touched.