A deep truncated cylindrical electrical box with angled molded-in internal mounting brackets on the flat side surface is mounted to the side of a wooden or metal beam. This internal mounting feature is especially of interest in old work to minimize the size of drywall cutout by limiting it to the outer contour of the electrical box. Any device, such as a paddle fan, will be directly supported by an exterior supportive L-bracket, not by the molded box itself. Replacing the L-bracket with a heavy-duty cold rolled steel bar bracket permits fastening between two beams. An alternate embodiment for the electrical box itself supports lighter loads by the electrical box itself.