Electrical plugs having single and double insulation as well as the method for manufacturing the double insulating electrical plugs are disclosed. The single insulated electrical plugs have internal walls which electrically isolate the electrical connectors. The single insulated electrical plug has a one-piece body with a central base which accepts the electrical connectors, as well as two covers hingably coupled to the base to secure the connectors in place. The double insulated electrical plugs are insulated by both an inner body as well as the overmold material. The inner body has vents which enable overmold material to be injected into the inner portions of the inner body as well as onto the outside of the inner body. During the manufacturing process, molten material flows over the outside of the inner body, and also flows into the interior of the inner body to provide two layers of electrical insulation.