Abstract: An interjoist hanger assembly for supporting items to be hung is formed of a pair of elongated tubular sleeves interfitting telescopically slidable one within the other. Supported at the distal end of each of the sleeves is an axial screw and a floating collar having circumferentially distributed axially extending prongs or teeth. The sleeves effect an interlock when collapsed whereby they can be rotated in unison for threading one end into an adjacent joist. When the sleeves are expanded, the opposite sleeve end can be similarly threaded into the opposite joist. With each threaded attachment, the prongs of the surrounding collar are drawn into a gripping engagement with the joist surface thereat.A saddle secured snap fit onto the outer sleeve includes side flanges to which an electrical outlet box can be mounted for attachment of an item to be hung.