What are some likely culprits due to a leveling light flashing on and off.

I tracked mine down to a pinhole leak in the line in the front passenger wheel well. I cut out the piece where the leak was, and rerouted the line slightly and put a brass coupling in the line with farels that fit the line perfectly.
I disconnect the leveling deal in the rear and ran the compressor putting soapy water on the coupling, the leak is solved but the leveling light still flashes.

Quite aggravating!