After working fine for many years, my garage door opener is having
sporadic problems. Replacing it is going to be costly and problematic,
so I want to take a shot at repairing it instead. Here are the
symptoms:

1) The door will occasionally open or close on its own.
2) The hard-wired wall switch is occasionally unresponsive; pushing the
button has no effect.
3) The remote control seems to work consistently; there's been no
problem with the remote.

From these symptoms, I suspected the wiring on the wall switch. (I
tried the easy and obvious step of changing codes on the remote in case
there was neighborhood interference, but this made no difference.) I
replaced both the wire and the switch itself, but the symptoms
continued. I then disconnected the wire for the switch completely, and
operated the door by remote only for several days. Unfortunately, we
still had the problem where the door would sporadically raise or lower
on its own.

I'm now thinking there's an electrical problem with the switch
connections within the motor casing itself. I unbolted the unit from
the ceiling, lowered it onto a ladder, and removed the cover for
inspection, but I didn't find any obvious problems. Of course, I
wouldn't know what to look for.

Does it sound like I'm on the right track? How can I isolate what the
problem might be? Thanks!