The family next door (1939)

Rose Pierce is discontent with her life as the wife of a small town plumber and has visions of becoming a wealthy socialite. Consequently, when her smart aleck son Sammy hears that an electric railroad line is to be built through town, she decides that the family can become rich by purchasing the lots along the right of way. Patriarch George Pierce laughs at the idea, but when Rose and Sammy learn that Cora Stewart, the wealthy town widow, has withdrawn her savings from the bank, they jump to the conclusion that she is interested in buying the lots, and mother and son secretly invest the family bank roll in the land.