You can easily re-purpose that thin plastic foam packing sheet into free wall outlet gaskets that keep warm air in your home where it belongs.
This will save you some utility costs and keep moisture from condensing in your walls and attic.
It only take about 3 minutes per outlet because there is no measuring or transferring of dimensions required.
This is a fun, satisfying, no cost, energy saving project. Cutting this stuff is a little like popping bubble-wrap. It's mildly addictive. I can quit any time I want.
Step 1: Simple Tools and Material
We re-purpose that thin (1-2 mm thickness) foamy plastic wrapping sheet that frequently is found around electronic products in the box.
It's made of HDPE (High Density Poly Etheline) or LDPE (Low Density Poly Etheline)
Tools: Scissors, Exacto or utility knife, Screwdriver
For safety you can turn off the circuit breakers. (So I hear.) [ Mrs. Woodenbikes calls me "Sparky"] But I digress....
Thrill-seekers can leave the circuit breakers on and stand in a bucket of water while doing the project blindfolded.
I'm kind of middle of the road on the safety spectrum.