Mary Callahan, sales-hostess in a fully-furnished model bungalow, has become so fond of the home that she wants it for her own. One morning she finds that an intruder has slept in the house all night. He is Jeff Langan, self-promoted super salesman...out of a job. A few evenings later, Jeff appears, seeking shelter from a driving rain, and he and Mary sit in the living room, listening to the radio and awaiting the end of the storm. The station is offering a contest promotion that gives $5,000 to the married couple writing the best letter explaining why they are the happiest married couple. Jeff and Mary decide to pretend they are married and send in a letter. A few weeks later Mary is notified their letter won and the donor will be dropping by their bungalow to give them the prize. Now all Mary has to do is find Jeff, who has been drifting from job to job, and then find a pair of kids to pose as their children...called the Little Darlings in the prize-winning letter...and a few other details to be handled before the donor shows up.