A cover assembly for covering an outlet box. The assembly includes a cover plate and an insert piece having a middle member and two retention members. The cover plate defines a cover aperture which receives the middle member of the insert piece from a back side of the cover plate. The retention members of the insert piece abut the back side of the cover plate. The insert piece may define a connector aperture for receiving a cable connector and may include designation figures. The assembly may also include a strap defining mounting apertures for receiving snap-fit connector modules. The strap may define shelves along two opposed sides for receiving the retention members of an insert piece. The strap may also define tab slots for receiving tabs of the insert piece.