Random time for material

Friends, do you have any ideas on how I can set a random time for the Light Function material?

write a small bp - add your light and control the random via random float or int, put it on a function timer. Or you could write a BP that grabs all the lights and sorts through the array and assigns random values for each light or group of lights. You could also trigger this so if a player runs across the trigger it sets off the BP.