Apparatus for facilitating mounting of an electrical box on an associated stud of an associated building which includes an elongated support comprising 1st and 2nd telescoping elongated support members dimensioned and configured for sliding for relative sliding engagement whereby the overall length of the 1st and 2nd telescoping elongated members is adjustable, the elongated support having 1st and 2nd opposed sides. A support plate is carried on the elongated support, the support plate is pivotally attached to the elongated support with at least a portion thereof extending laterally with respect to the elongated support whereby pivotal motion of the support plate positions the portion from the 1st side to the 2nd sides of the elongated support. Engagement surfaces on the portion are dimensioned and configured for engaging an associated electrical box.