What's happening?

Alfred Hitchcock Presents: 2x39

The Dangerous People

Mr. Jones and Mr. Bellefontaine wait for a train at a train station. Both of them have heard that a dangerous lunatic has escaped from a local asylum and each suspects the other of being the lunatic in disguise. They grow more paranoid and worried. A policeman arrives and both try to convince him that the other is the lunatic. The policeman says that the madman has just killed a policeman and has stolen his uniform. Jones and Bellefontaine realize the policeman is really the lunatic in disguise. They subdue him and get the real police.

Alfred Hitchcock Presents: Season 2 Episode 39
Jun. 23, 1957