After inserting the second Madison Bar the protruding edge of the metal electrical box needs to be pushed hard against the wall as the Madison Bar is pinched over. You can use a large flat head screwdriver for this, the bigger the easier. This ensures that the box will be held in place tightly. Use needle nose pliers to crimp the Madison Bars tightly against the metal electrical box.
Home Electrical Receptacle Box Installation in an Existing Wall Using Madison Bars MadisonBarInsertionLeftSide-Copyright-IMG_1144-460x613