The Man Who Wasn't There (1983)

Being invisible gets you into spy rings, diplomatic circles, and the girls' locker room.

When he accidentally takes possession of a top-secret invisibility potion while en route to his wedding, government bureaucrat Sam Cooper finds himself engulfed in a madcap free-for-all as Russians and other bad guys try to get the substance. To elude the Reds, his own State Department bosses and his livid fiancée, Cooper takes the vanishing juice himself—which only makes matters worse.