Evidence 1 : When the neighbors saw Mr. Goodmans car started up by it's self.
Evidence 2:When everyone was blaming each other when they didn't know who it was.
Evidence 3: When the whole maple street started fighting over who was and wasn't the monster
One of the main themes of the Monsters due on Maple Street by Rod Sterling is Man is their own worst enemy. Some evidences that are in the text that give this information is when Mr.Goodman's car turns on all by itself. Then everyone was blaming each other when they didn't know who it was. The final evidence from the text and film was when the whole Maple Street started fighting over who the was or wasn't the monster. After all the power went out Mr. Goodman's car turned on out of no where. At first everyone blamed him but then his car turned off and the lights in Charlie's house. Then everyone was pointing fingers and blaming Charlie and Les of being the monster since they all got power. After this happened nobody knew who was the real monster and had a riot of chaos and destruction on Maple Street. from these evidences you can see how the theme "Man is their own Worst Enemy" relate to this story.