The invention pertains to an electrical box assembly having a support structure for use in securing electrical enclosures, housings or boxes or the like to a stud. Upon insertion of the stud into a stud-receiving cavity of the assembly, a movable tab is pivoted to press one or more prongs into engagement with the stud. Pivoting of the tab may continue until the tab is locked in place whereupon the electrical enclosure is secured to the stud in compliance with code requirements without the need for such secondary operations as driving a separate fastener into the stud; the box now being secured with sufficient rigidity to satisfy local code enforcement.