A self-contained or boxless electrical wiring device, such as a receptacle or switch, includes a body adapted to be mounted in an aperture in the wall of a building or a mobile home. The body houses wire grasping terminals for connection with the wires of electrical cable without requiring the stripping of insulation. Interior partitions support terminal members into which the insulated cable conductors are forced for terminating the device. The partitions are integrally formed with the front face and side walls of the body in a configuration which is readily molded. Mounting members, in the form of mounting pawls or crimp mounting members are formed at each end to permit installation near wall studs. The body is closed by a back cover having projections for driving the wires into the terminals, the cover being releasably secured via legs which engage the sidewalls.