First-time poster here. I have spent the better part of my evening looking for info on a UM segment that I seem to recall airing back in the early or mid-'90s, although it may have been made earlier for all I know. The segment detailed paranormal goings-on in what might have been a laboratory or government facility. What I recall most vividly is a red, male apparition in a hallway. This terrified me as a child. I also remember a gate or doors swinging open and shut without any apparent human intervention. If anyone can tell me more about this segment (assuming it did, in fact, air on UM), I would greatly appreciate it.

Don't recall a segment that had a red, male apparition in a hallway and the swinging doors don't sound familiar either. Sorry.

The red male apparition you are referring to may be the Mothman which was supposedly seen several times in Point Pleasant, West Virginia.

What I recall most vividly is a red, male apparition in a hallway. This terrified me as a child. I also remember a gate or doors swinging open and shut without any apparent human intervention.

Are you sure your not referring to the re-aired "In Search of.." episodes back in the 90s on A&E?

I remember one episode of that show involving something about a red ghost.
I think it was the Haunted Castles episode.