That's a little creepy. I think I'd be weirded out if I saw the vent controller moving back and forth by itself, for no good reason.
You gotta nip that gremlin in the bud quick, before it spreads to the rest of the vehicle.
I would agree with the short, but tracking them down, can be both difficult, and time consuming. It could also be the charging system.
If your alt is not putting enough back in, the vehicle is going to act up. I had a similar situation with a grand am. gauges would go nuts, doors would lock, and unlock while driving, and interior lights would come on and off. Replaced the alt, and it was fine.