Humidity issues


I have a teensy 4.1 that lives is a "weatherproof box" on a roof for an old Neon sign that I repurposed using LED strips....
the box is apparently not weatherproof as every time there's a heavy rain it fails and the sign stops turning on, after coming up to diagnose the problem I get to a dead board that is not turning on, after a cleanup and letting it dry, it comes back to life but its reverted to the blink code. I am suspecting moisture shorting out the pushbutton or something of the sort.

has anyone experienced similar issues?? I am trying to rule out any moisture getting in the box to really be sure its humidity that is getting in there, but would like to pick your brains for any experience with similar issues.

I've had similar problems, due more to power cycles than humidity. In my case they are teensy 3.6 processors that are indoors. I just had another teensy 3.6 lose programming, in a totally different project than the ones described