The Skinny
I discovered an ingenious DIY energy saving product this week and wanted to share for those of you who may not have heard about it. The product is called a foam electrical outlet gasket and they make them to fit your plug and switch plates. You can find them at your local hardware store and they are very easy to install. Foam outlet gaskets minimize air leaks and can reduce your heating and cooling bill by as much as 20%. For most homes & professional buildings, these recurring small leaks add up to create an effect equivalent to leaving a window open, all day,
all night, and in all seasons. 
The Test
If you place your hand over your outlets in the winter on a windy day, you will feel cold air blowing through them. The purpose of foam gaskets are to seal off the wall cavity behind outlets & switch areas from the living space. Outside walls should be prioritized but it is also beneficial to seal inside outlets also.
Installation
To install an outlet gasket you simply unscrew the switch plate, place the gasket over the switch and reinstall the plate. Each one should only take a couple minutes at most. The gaskets usually come in a pack of 10 or more and are either universal, switches or plugs.
More Information:
Sealing Air Leakage
US Inspect – Foam Outlet Gaskets
Good Common Sense
Totally doing this next!!! Thanks for sharing this awesome information! <3
Why did I not know about this before!? Good info thanks for sharing!