Abstract: A subplate for installing a low-voltage electric receptacle plate onto a wall opening includes tab portions extending inward from clearance holes located centrally on the subplate frame. The tab portions each have two parallel lines of bend, a screw-engaging hole, and a clamping end. During installation, the tab portions are bent inward into the wall opening along the first bend lines and then backward along the second bend lines to position the tabs' clamping ends against the inner wall surface. The receptacle plate is then screwed to the subplate through the clearance holes and the inner screw-engaging apertures, tightening the clamping ends of the tab portions against the inner surface of the wall.