Abstract: A system for sealing a building electrical outlet of the type mounted within a wall surface of the building having one or more electrical plug sockets adapted to receive an electrical plug and a cover plate. The system includes two primary components. A gasket formed of an elastomeric material is provided with a pair of electrical terminal slots. A plug cover element forms a front cover panel and includes a pair of tabs extending from a back of the face surface to engage the electrical plug socket terminal slots. Two modes of operation are available. When an electrical plug is inserted into the electrical plug socket, the gasket is positioned between the plug and the socket to seal against air infiltration. When an electrical plug is not inserted into the socket, the plug cover is used to maintain the gasket in position for sealing against the electrical plug socket.