I added a cap across the photo button terminals to try to prevent the false triggers, not expecting much.... And it didn't work. So, I decided that the solution was in software. I added a sleep in the callback functions tied to the button presses. The photo button sleeps for 0.1 seconds, then checks to make sure the button is still low. The shutdown button checks after 3 seconds to make sure you really meant to power off the unit. That did the trick! No more weird triggering due to light switches, power pulses from the AC, or just random noise. Now I just need to add some finishing copper trim to the box and find any last minute bugs. I think this project is in the home stretch!