An electrical box assembly that includes a box body having a screw mount aperture and a base insert slidably coupled into the box body. The base insert may include a back wall, and the back wall may have an electrical device aperture therethrough, a box mounting screw aperture therethrough, a center mounting screw aperture therethrough, and a rear face. The rear face may include a center mounting plane at the center mounting screw aperture substantially parallel to the back wall and at least one spacer extending above the center mounting plane from the rear face at the box mounting screw aperture. Other particular implementations of an electrical box assembly may include at least two removable flanges coupled along a front side of the box body.