Unfortunately, the lights are on the eaves of the house - over 20 feet high.
Tried flipping breakers that were not labeled for major appliances and the like. Didn't help. Tried reprogramming the damned thing. That didn't help either.
My guess is that there is some internal defect in it. Or that the battery is in the process of dying.
Even if unscrewed all the bulbs, the clicking noise would continue.
The batteries are not accessible - the box for the switch doesn't appear to have any access to the batteries.
Can't figure out which circuit breaker goes to these lights.
My husband is on the verge of cutting the wires to the switch - the noise is really aggravating and he figures we'll have to call an electrician to deal with this anyway.
He did it, and capped the wires. The lights are (thankfully) off. The switch is still clicking, but we threw it outside on our porch so we can sleep. I'll call our regular electrician on Monday and have him replace it with a Honeywell which has the virtue of a readable screen and what seems to be a more intuitive programming capability.