Have a Fan Light Night Light just above my shower stall. Went outside this morning and I have a huge icicle in my gutter just below the roof cap exit for fan. Took the fan down from the ceiling and tried to insulate the housing. There is a 4watt incandescent bulb for a night light and a 26 watt fluorescent light. They are both housed in a metal cabinet. How would I insulate the housing to prevent heat loss thru the duct. I am reluctant to use duct tape or anything flammable to stop the flow to the outside. We have stopped using the fan and only use the night light sparingly.