bracket 11 a is in installed position top mating interface 12 a not shown rests against the electrical box top inside surface 26 a while side interface 14 aa resting against a flat portion 21 a of electrical box sidewall screws 24 are driven through bracket 11 a and sidewall 21 a into the structural member to secure the bracket 11 a into installed position bracket 11 a is designed to reinforce two particular box types fig3 a 3b and 3 c herein after fig3 shows a three inch plastic electrical box 20 b with bracket 11 a intalled therein with fig3 a showing a perspective view through the electrical box opening fig3 b showing a view looking at the bottom and fig3 c showing a sectional view through axis 3 electrical box 20 b also includes flanges 22 b for fastening the box 20 b to a structural member by way of nails 23 for this box the installation position of bracket 11 a also brings top mating surface 12 a not shown against electrical box top inside surface 26 b this electrical box 20 b includes a boss 25 b for insertion of a mounting screw whereby a fixture may be attached to.