Hello all,
I had a real strange issue with my turn signals changing speed back and forth and would click after shutting off. It was there very first sign of my battery getting week, because my alternator was dying and took about two weeks. Make sure you do not have any fluctuation in your voltage. I would just to check.
Does the car maybe have some kind of alarm, and or maybe some one unplugged the horn/siren? just another thought.