Lightning triggering a wired input?

Had some wierd behavior last night dirung thunderstorms with a LOT of lightning nearby (less than a mile.)

I have it set up to beep the piezo whenever a wired input changes, and it was beeping all during the storm.  The frequency of the beeping seemed to more-or-less follow the intensity of the nearby lightning.

Anybody seen anything like this?

I'm having the same issue and hoping someone will have a solution out there!