Mysterious man, secret powers and shrunken man in a bottle - spoilers

[wositelec]

I'm looking for a movie - it is maybe from 1970-1995, probably USA . The main character is a guy has some kind of secret powers? He was an evil trickster and had a gallery exhibition, or had some kind of museum to which he invited a friend? The final scene - the guy is in some museum, or there invites someone. They are arguing and this let's say bad guy grabs him and crushes him, miniaturises him to a size of about 10 cm, pushes him into a vessel (maybe a jug or a bottle) and also puts him on display as an exhibit. Some people come in who are visiting this museum, maybe a gallery and he bangs on the walls of this vessel, but nobody hears him, he's so tiny.

Every help will be appreciated.