Abstract: An RF shielded housing for a signal distribution system component includes a cast metal base member which forms an interior chamber in which circuit elements of the component are contained. An access aperture is provided on one wall of the housing to facilitate installation of the circuit elements within the chamber. The access aperture is closed by a cover plate which fits over the aperture into a flange portion provided in the base member around the periphery of the aperture. A number of closely-spaced sawtooth-shaped engaging elements integrally formed in the flange portion deform the cover plate as it is press fit into position against the flange portion to form a like number of closely-spaced mechanical and electrical engagements which hold the cover securely in place and prevent RF leakage from the circuit elements within the chamber.