Invented by hardware store owner William H. Rubely in the late 1800's and initially called the "Tuckahoe Toggle Bolt" , the toggle bolt has been used whenever you need to mount something to a non-structural, hollow, thin wall where a screw would simply pull right out. A toggle bolt has wings like a butterfly that fold closed against an internal spring to be inserted into the wall. Once through the wall, it snaps open and provides a secure are wide surface area to fasten an object to the wall using the attached a threaded screw. You'd see it used in sheetrock or wood applications holding a fire alarm box, a speaker to ceiling tile, a bulletin board, etc. When the screw is removed, the wing simply drops behind the wall to the floor below and is abandoned.