Did he look like this?

[![DVD season 1 cover][1]][1]

(Note the red t-shirt.)  This is the Sci Fi channel (note contemporary spelling) series ["The Invisible Man"][2]  It originally aired 2000-2002.

Darien Fawkes (the titular character) could control his invisibility, so he could have turned it off on the way into the building.  The building could have been the Agency that he works for.

  [1]: https://i.stack.imgur.com/gT3In.jpg
  [2]: https://en.wikipedia.org/wiki/The_Invisible_Man_(2000_TV_series)