Hang a hook or bracket to a hollow wall (for example, sheathed with plastic or plywood) is always a problem: fixture does not hold in this place is quickly loosened and popping up. However, such a charge would be reliable, if drilled in a wall of the notched hole to insert one end of thin metal or soft plastic tube inserted into her bolt as shown in the figure. Screwed nut make “raskladyvaetsya” pipe and the bolt head got stuck in the hole firmly and securely.