An electrical box assembly is provided. The electrical box assembly includes an electrical box and a support bracket positioned proximate the back wall of the electrical box and coupled to the electrical box. The support bracket includes a plate member and a cable management member extending laterally from the plate member and forming at least one pass-through opening sized to receive an electrical cable. The plate member includes a bending line that divides the plate member into a first portion and a second portion. The plate member has first and second configurations. The plate member is generally planar in the first configuration. When the plate member is in the second configuration, the first portion of the plate member bends along the bending line and extends laterally from the second portion to engage a second wall opposing the first wall and opposing the back wall of the electrical box.