Re: Sealing Ceiling Fan Electrical Box
If the blown-in insulation is fiberglass, there is no short-circuit or fire hazard concern.
Sealing the boxes should be done to block airflow for the purpose of energy efficiency**. Cheap adhesive caulking ($2/tube) works just fine for this.
Insulation can safely come in contact with standard electrical boxes. Only recessed lights that are not rated for direct contact with insulation require an additional box around the fixture for energy efficiency and to prevent insulation contact.
**Regarding energy efficiency: in the summer, it keeps cold air in and warm air out. In the winter it keeps warm air in and cold air out.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.