A receptacle box installer includes an L-shaped element with a first arm and a second arm, a block attached to an inside surface of the first arm of the L-shaped element, and a gap between a side of the block closest to the second arm of the L-shaped element and the second arm of the L-shaped element. A user then inserts the second arm of the L-shaped element into a receptacle box until the gap is filled with an outside wall of the receptacle box. A surface of the block opposite the connection with the first arm of the L-shaped element is contacted with a front surface of a framing member. The receptacle box is then contacted with the framing member. A user then attaches the receptacle box to the framing member using standard attachment means. Once the receptacle box is installed on the framing member, the receptacle box installer is removed from the receptacle box.