I have 4 HS200 switches mounted together, all fed from the same circuit.  The switches work fine generally, but when that circuit is shut off (at the breaker) all 4 switches start clicking continuously, maybe 2 clicks per second.  This goes on for several minutes - I didn't wait to see if it would stop eventually.  There is no voltage on the hot wire.  Any idea of what is happening, and whether this is normal behaviour?