A wall-mounted electrical-connector-engaging assembly for axial engagement with an electrical connector, the assembly including (a) a wall-surface adapter having front and back faces and attached to a wall over an opening in the wall and (b) a backcap. The adapter back face has a plurality of wire-connection points for installation of a corresponding plurality of wires, and the adapter front face has a plurality of slidably-engaging electrical connection points for engagement in at least an axial direction with the electrical connector. The backcap surrounds the plurality of wire-connection points and adjacent portions of the corresponding plurality of wires connected thereto, and includes a twist lock for installation on the wall-surface adapter.