Dusk dawn lights are constantly on!

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.

I've had similar problems with motion sensor lighting. Sometimes turning the power off and then back on "resets" something in the sensor which clears the fault.
If not, the sensor will likely need to be replaced.

Make sure the sensor is clean and free of debris. I had some busy spiders that managed to cover my sensors with webs. After cleaning them things worked much better.

Turn the circuit breaker off for at least 10-seconds, then turn it back on. On some, a quick on-off-on sequence tells them to stay on. This could happen if the power hiccuped just so. Shutting them off resets them, if it is off long enough, and that's what happened.