There was a time when people would regularly save money at home. Although most people do not keep large amounts of money in their homes in a shoebox, some still do. It is most likely to be seniors who either lived through the Great Depression or had parents who did.
Many banks collapsed during the depression, and people knew that they did. It quickly caused people to distrust banks or similar financial institutions. Those who lived during that time started hiding money at home, hoping others in their household would not find it.