That's Not My Neighbor

It's 1955 and you're working in the reception of a residential building. So far, so unspectacular. However, the entire world is currently being overrun by alien creatures that often disguise themselves as doppelgangers of real people. Your task is to carefully check out every inhabitant of the house before you allow them in. And if something seems strange to you, report it immediately. They are relying on you!