For 3 years in this home this never happened. Our 3 dusk dawn exterior lights were flickering on & off a few nights ago and now they won't turn off at daytime. THere are 3 lights, and all remain synched. THere is no actual switch, just the dusk dawn sensor. The only variables I can think of is earlier that day I took down my exterior christmas lights that were mounted in the vicinity of the sensor fixture which is mounted facing down on the exterior ceiling above my porch. The other is that there is snow/ice buildup on the roof above that area, but not in visible contact with the sensorfixture or the sensored light fixtures. The lights are constantly on. Any ideas? If the sensor was damaged when dismounting the christmas lights, would the extrior lights remain on constantly like this? THanks for you help.