It’s winter. Put your hand up to an electrical outlet or light switch in an exterior wall. Do you feel some cold air coming in? If so, there is a quick and easy solution. Pick up a pack of foam outlet and switch covers from a home store and put them behind the plates. No more air infiltration. If your electrical boxes are set behind the drywall, it is really that easy. If you have remodel boxes that sit just proud of the drywall like the one shown above, I find it helps to trim the foam down to size so the plate can fit snugly against the wall.
I put the foam onto the receptacle, press on it to make an imprint of the box on the foam, and then cut around that imprint line. I leave about an extra millimeter or two around the line to make sure it’s a snug fit and no air can get through. The edges can be tucked into the box. If you haven’t turned the power off to the circuit, just be careful not to touch the sides of the receptacle so you don’t get a shock.
Once the plate is back on, it looks just the same as it did before, but no cold air comes through. It’s a simple and inexpensive way to save a little on heating costs.