I watched the show in the 90s possibly early 00s, and it didn't seem like it could have been made any earlier than the late 80s.
The show was part of an episodic mystery show like Outer Limits or Twilight Zone, or possibly X-Files? I've tried to look for the episode amongst that back catalog, but so far no joy. In this episode I think a man had been abducted by, or had been accused of associating with aliens in some way?
The point of the episode was, until the last scene, it was never confirmed if he had actually interacted with aliens, or any of his claims of going beyond human limitations were true.
The episode closes on him speaking through a window on the secure door to a military personnel, disagreeing over the nature of his imprisonment. Then the scene cuts to inside his cell, and he's actually levitating.
What was the show and episode I am trying to remember?