Abstract: A support for mounting an electrical outlet box in an aperture in a building panel, said support comprising a U-shaped yoke having a base portion, a pair of legs substantially normal to the base portion and a support foot extending outwardly from each leg substantially parallel to the base portion and adapted to overlie an area of the front of the building panel adjacent the aperture when the yoke is inserted in the aperture, each leg having at least one aperture intermediate the base portion and the foot; and a clamping member for association with each leg of the yoke, each clamping member having a support surface adapted to overlie an area of the back of the building panel opposite the area of the front of the building panel to be overlaid by the foot of the associated leg, a tab member extending from said support surface and adapted to interconnect the clamping member with said at least one aperture of the associated leg, and a clamping arm extending from the support surface on each side of the tab member,