https://www.snopes.com/fact-check/track ... X_PlsWKINc
A synopsis of the episode from the Classic TV Archive reads as follows:
Walter Trump, a confidence man, puts on a long robe and holds a tent meeting in the town of Talpa. He tells the townspeople that a cosmic explosion will rain fire on the town and that he is the only one that can save them from death. Ranger Hoby Gilman attempts to prove Trump is a fraud.
A relevant portion of dialog from this episode has been transcribed below:
Narrator: The people were ready to believe. Like sheep they ran to the slaughterhouse. And waiting for them was the high priest of fraud.
Trump: I am the only one. Trust me. I can build a wall around your homes that nothing will penetrate.
Townperson: What do we do? How can we save ourselves?
Trump: You ask how do you build that wall. You ask, and I’m here to tell you.