I just saw an episode of Adam 12 (of course maybe I should post it there as well but...) episode entitled "Extortion" (Season premiere Season 4) and there was a guy on there that looked just like a young Paul Benedict. In the credits, there's a guy on there named Nick Benedict.

Any relation?

I don't think so, but I could be wrong.

Nick Benedict is the son of actor/director Richard Benedict. Richard Benedict's real name is Ricardo Benedetto. So Nick and Paul Benedict are almost certainly not related.