There are no pictures or video of this program and very little has been written about it. I did manage to find an article on Light’s Out host Frank Gallop that referenced Trapped:
In accordance with Gallop, other hosts who aimed to set a mood of terror at the time included Andy Christopher […] (Mr. Black), James Monks (Tales of the Black Cat […]) and Lee Bowman (Eye Witness […]). Similarly, Jack La Rue (Lights Out), Boris Karloff (The Boris Karloff Mystery Playhouse) and John Carradine (Trapped: Tales of the Supernatural […]) offered external examples of film stars hired for TV hosting roles in which an emphasis was placed on their associations with the horror genre [with] typecasting as villainous and/or monstrous characters as part of their respective series façade. Due to a lack of surviving/missing material associated with some live series pre-1955, in the cases of some hosts, it is not always possible to definitively discern to what extent horror elements were adopted as part of a series persona.
Frank Gallop: The Ghoulish Host of Lights Out Thomas Wilson Taylor & Francis Online Historical Journal of Film, Radio and Television March 20, 2020
After approximately eight minutes on screen and a quick promotional plug for his new film G.I. Blues, Presley was gone. The remainder of the special consisted of performances by the additional guest stars. Excerpts from this show appear in Warner Bros. 1981 documentary film This Is Elvis.
Trivia Bit:
♦ Elvis got paid an at the time incredible sum of $125,000 for only a few minutes of onscreen time.