I know this is a long-shot, but if you have any accessories plugged into any power receptacles (like a cell phone, radar detector, GPS, etc.) unplug those things and see what happens. A cell phone charger appears to have been the culprit making my compass, DIC, and radio lights flash and my headlight control module click. My problem was a bit different than yours, but when it comes to electrical gremlins things can be as mystical as radiation effects testing!
It'* worth mentioning, anyway, and if you do have something plugged into your dash it'* and easy check to make.