If you have a motion light that continuously turns on and off, it may be caused by heat or light being reflected from other objects. If it is windy outside, leaves or other objects may be blown across the motion path of the sensor.
The solution to this problem is to reposition the reflecting lamp heads away from the sensor. If the sensing dial is set to high, decrease the setting or reposition the motion sensor.
-3rd Year Electrician Apprentice, Todd