Hello:

I have a 30 year old ranch house in New Jersey. I'm planning on
continuing the previously started task of sealing all opensing from the
living spaces into the attic for air infiltration.

I understand about caulking/sealing all wires, pipes and such. What I'm
not clear on is how to seal the electrical boxes that my ceiling fans
are mounted to?

I have a ceiling mounted fans or light fixtures in most of the rooms
around the house, and there are gaps around the boxes. I know I can
caulk/foam these gaps but what about all the individual holes in the
boxes themselves? The boxes are a mix of metal and plastic boxes.

Can I lay some poly sheet over the box and lay the insulation
over/around it? I hesitate to do this because at least 2 of the
fixtures are mounted directly to the boxes (not ceiling fans or pendant
lights) and there might be heat build up.

I see a lot of discussion on this subject for sidewall application, but
very little for ceilings.

Any help would be appreciated.

Jim