A pin and sleeve receptacle is mountable in a wall box recessed in a wall opening of a building with wires extending into the box from an in-wall wiring passage. The receptacle has a tubular electrically non-conductive shell closed at one end, the other end being open and a flange with fastener openings at the open end of the shell. A cylindrical inner body has an outer diameter smaller than the first inner diameter, the inner body having female connector sleeves for receiving electrically conductive pins of a mating plug. The inner body is mounted within the shell with an annular gap surrounding the inner body for receiving the shroud of the pin-and-sleeve plug. The opening at one end face the same direction as the open end of the shell to receive the pins of the plug. Apertures in the shell admit wires from the box for connection to the electrically conductive female connectors. An adapter plate has a central opening to receive the shell, holes to receive fasteners extending through the fastener openings in the flange and holes to permit passage of fasteners for mounting the plate across the opening of the recessed wall box. A cover plate has a central opening surrounding the open end of the shroud, openings for passage of fasteners for attaching the cover plate to the adapter plate with the flange in between, and sloping side edges for abutting the wall surrounding the box to form a minimally protruding assembly. A right-angle plug having pin connectors to mate with the receptacle to form a connector assembly with minimum protrusion from the wall is disclosed.