Possible Static Issues

[mribble]

I've made a electric spinning wheel (the kind that turns wool into yarn).  You can see a few images of it below.

A few people using it have issues with it randomly turning on/off.  After rebooting everything continues working.  I'm starting to wonder if it has to do with static electricity building up and then shorting to the circuit board or switch.  I don't have any experience with this sort of thing.  Are there some best practices for designing circuit boards to resist static or things I could do to the enclosure to help with this?  Even if you have idea on crazy hacks to protect it (tin foil) or maybe some kind of spray you could put on the plastic case?  The plastic case is mostly glass reinforced nylon if that matters.

I've attached the pcb schematic which is pretty simple.  The brushless motor controller is inside the metal motor case and I suspect that is fine against these sorts of issues.  The pcb itself is just a 2 layer design with a ground plane on the top layer.

The issue that makes this hard to debug is I still haven't been able to reproduce the problem locally and only a few people have seen it.  I would like to have a little more knowledge about this before I start to have users who can reproduce this test things.  Internet searches didn't point me to very useful things, but I'm happy to read existing documents if people know of good sources that might be useful.

If you folks have any suggestions I'd much apricate it!