In "The Monsters are due on Maple Street" you can tell that it takes place in a different time period because a lot of the technology in the script was used a long time ago. For example, plug-in lawnmower, and a phone with a rotary dial.
Maple street is the main setting in the story, but it never says exactly what state it's in or if it's even in America. So this location is made up, and nonexistent in the real world.
There are multiple reason why technology is important in this story. One example of this is the spacecraft that the aliens come on because it's what started the story. The spaceship has the power to turn off other pieces of technology that belong to humans. Once humans see that their technology is gone, they start pointing fingers and threatening people who they think are to blame for it.
After the aliens turn off the power, humans start suspecting each other as aliens, and they start fighting over who did it. By the end of the book, people are fighting and yelling at each other, and one person even gets killed.
The antagonist is not one person, or even the aliens, but the humans all together. It was them who let themselves actually believe that people they knew for a while were aliens. It was them who killed each other over who was an alien and who was not, and it was them who cared about their technology so much as to assign blame for who was responsible for taking their power.
Aliens are another element of science fiction in this story. The planet they are originally from is unknown, but we do know that they plan to invade earth because they were the ones who took away the human's power. They knew humans would tear each other apart over it. All they had to do was sit back and watch