I tried but it won't work...
Try this [Add a point light in a part or something]
Wait(1) script.Parent.PointLight.Brightness = 30 Wait(1) script.Parent.PointLight.Brightness = 0 -- If this doesnt work put while true do and a end
Just set the Enabled property to false to turn it off, and to true to turn it on.
By the way, in your script, you didn't have any ends to close the loop and function.
local light = script.Parent.PointLight while true do wait(math.random(0.8,1.8)) light.Brightness = math.random(15,30) wait(math.random(0.8,1.8)) light.Brightness = math.random(0,5) wait(math.random(0.8,1.8)) end