On of the main themes on The Monsters are Due on Maple Street by Rod Serling is do not make assumptions if you do not have proof. In "The Monsters are Due on Maple street" people made assumption event though they did not have any proof and that turned everyone against each other. All of the neighbors accused Les of being the monster because his car started when nothing else on the street worked. When Les Goodman's car turned on people thought oh he is the alien when they might forget that however the alien was could have been doing that so that all the neighbors would think that it was that person. Also when the lights turned on in Charlies house all of the neighbors accused him of being the alien.
Evidence 1: All of the neighbors accused Les of being the alien because his car started.
Theme: Do not make assumptions if you do not have proof
Evidence 2: Everyone just assumed that if anything weird happened that the person was the alien.
Evidence 3: Charlie shot Pete becuase he assumed that Charlie was the monster.