Perhaps to nurse them. Or perhaps as just company and a form of security. To get on with someone, just refer to the Personals in your newspaper or write your own ad. When I used to live in LA, there was this person constantly bothering me for money. Just to be sure that he doesn't find me here to bother me again, it is important to me to live with as low of a profile as possible.
Many homes have attics and-or basements that can be easily adapted to hiding a person or people.
And other places in a home an be modified to at least temporarily conceal a person. If the home has a crawl space, a trap door can be made so that a person can quickly slide underneath the building for a short period. Another excellent method is to wall over a closet, and then to build-in some secret means of entry. For example, many homes with hallways have hall closets. However it's not unusual to not find a hall closet in a hallway.