I got this item in a bidding lot and have been trying to figure out what it is ever since. The nearest I can tell it is either an electro shock therapy device or perhaps a remote detonator. It has brushes and a fluted cylinder. Very heavy cylinder with a handle to spin the cylinder and an electrical contact is what it appears to be On one side. Has a ground lug.
I haven't tested for current since one of the brushes is missing.