I know this may not be the right place to ask a question like this, but I'm always happy with the advice I get here.
During the day I play my guitar amp with no issues. However, at night I have feedback problems. This only occurs at night, and I cannot recreate the problem during the day (turning on lights, other electronics, etc.) Also, this occured with a battery powered amp as well, so I don't believe it to be a electrical issue with the sockets.
Could someone be transmitting some kind of strong signal in my neighborhood? It's so bizarre it only occurs at night.