A useless machine or useless box is a device whose only function is to turn itself off. - Wikipedia
A Rube Goldberg machine, named after American cartoonist Rube Goldberg, is a chain reaction–type machine or contraption intentionally designed to perform a simple task in an indirect and (impractically) overly complicated way. Usually, these machines consist of a series of simple unrelated devices; the action of each triggers the initiation of the next, eventually resulting in achieving a stated goal.
Useless rube goldberg machines