Revealing mistake: When the show introduction focuses on the front door, the Frankenstein sized and shaped cut out area can be seen where Herman is to make his appearance.
Revealing mistake: As Herman stands on the porch after Spot runs off, he stomps his foot. As the light fixture hits him on the head, it's obvious that the person hit was his stunt double.
Herman's Peace Offensive - S2-E15
Revealing mistake: When Herman punches the wall, his fist goes through the facade, and after he pulls his hand out, the support structure can be seen.
Herman, the Tire Kicker - S2-E28
Revealing mistake: As Herman lifts the VW Beetle, the shadow of the lift arm can be seen on the ground under the left side of the car.
Revealing mistake: After the car hits Herman, it falls apart. After the left front tire falls off, the prop holding up the frame is plainly visible.
Revealing mistake: Herman's wig flips up and down when hit by the car and lying in the puddle.
Revealing mistake: When Lily pulls in the sheets that Herman used to run away, the background doesn't show the house across the street or any of the town. Rather, it's blank, with shadows of the tree branches outside the balcony.
Answer: The comedic gimmick of both "The Munsters" and "The Addams Family" television shows in the 1960s was that both families were convinced they were normal and everyone else they encountered was odd. The Addams Family, for example, thought their "normal" visitors were mentally unbalanced because they always fled the Addams' weird home in panic. That was a running gag throughout the entire Addams Family series, so much so that easily half of nearly every episode was devoted to the predictably terrified reactions of their visitors (always accompanied by identical canned laughter). Meanwhile, in the Munsters' universe, the family thought "normal" people were physically deformed and even quite hideous. For example, the Munsters believed that their beautiful niece, Marilyn, was socially handicapped by her ugliness (the exact opposite of the truth); and, in the episode "Just Another Pretty Face" (S2E17), when Herman Munster was temporarily transformed into a "normal" person, his entire family found him utterly repulsive. The family's hidden revulsion to "normal" people was the running gag of The Munsters.
Charles Austin Miller