In the name making my HVAC more effective, may i ask a question about plywood in the attic. The house has a 10x6 x4 foot deep sized built in wooden display case, with an area for a minifridge. To spare you details, the built is connected to openings to the attic with no insulation. It causes a great deal of "ventilation" to leak all around and between the entire built in. The opening from the display case, to the attic is irregular--parts of rafters are in the way. Its not like i can easily just throw a roll of insulation over the area. I would need cut plywood into strips and squares, nail them in place, then lay insulation over it. Can i do this with plywood, or do i have to use drywall which i am less familiar with? I'm specifically worried about risk of fire? There is a recessed light in the built in, but the plywood i would overlay would be about 2 feet above it/then insulation.

I am a white collar type guy, and I would hire someone to do the job, but i'm not sure who would do it right---I have a feeling by the time i spent talking and interviewing people, it would be easier to do myself.