The Silent Alarm (1993)

It looks like 1950s suburbia: kids at play outdoors, an ice cream truck, detached homes with liquor cabinets and Danish modern furniture. A boy watches a strange man get out of a convertible and go into the boy's house to talk to his mom. The man is selling a home-alarm system, and that's not all mom is buying. She also buys his line, and soon he's moved in. But something isn't right, the lad's silent alarm keeps going off, even though the man treats the boy like a son, hosts barbeques for the neighbors, and brings a smile to mom's face. When the boy sees the man going through mom's jewelry, he knows he must do something. But what can he do?