Turn down the lights and enjoy a bonus episode just in time for Halloween. Two chilling stories from Suspense, “radio’s outstanding theater of thrills,” should help to get you in the trick-or-treating spirit. First, Orson Welles’ cross-country trip is hindered by “The Hitchhiker,” originally aired on CBS on September 2, 1942. Then, Ray Bradbury’s eerie story comes to radio life in “Zero Hour,” originally aired on April 5, 1955.