Good warning! I haven't used them, but have seen them in some coop pics. I wonder if LED rope lights (if they exist) are as bad.
They all get too hot in my safety-conscious mind. Just too many fire horror stories for my comfort zone.
@Granny368W, it might be a good idea someday to have an electrician tap into your wiring and add a plug inside the coop, so you can make use of a timer.
I'm a bit old-fashioned and prefer to account for all my chickens after dusk so a timer light or an auto pop door are moot for me - plus our yard is so small that anything automatic or electrical wouldn't add to the ease of care I now enjoy. The porch light between the house and the coop have been good for 5 years to keep away night critters and give diffused light for the coop interior. The automatic security light at the back yard only works to turn on in a wind storm but if something moves in the back yard it refuses to light up - go figure these new-fangled gadgets that don't work half the time!