The Alfred Hitchcock Hour 3x15

After Robert Manner's attempt to kill himself is ruined by a fireman's net, he is invited to join a suicide club headquartered at the Thanatos Palace Hotel. The members of the club have agreed to kill each. The catach is that the victim never knows who the killer will be and never knows when the murder will occur. Robert joins the club, but falls in love with one of its members Ariane Shaw. He gets a new lease on life and decides to undermine the club in order to prevent his own death.