I'd like to recommend to check out servas.org.
Even though the standard is to stay no longer or less than 2 nights it is possible to contact members and ask for longer stay.
Many members of all ages, with empty guest rooms and some even have time to show their area.
We have been member for 20+ years, then dropped out as I missed the yearly registration deadline.
Now as ER we will get listed again as hosts. For those who have a guest room, maybe even with a 2nd bath, it is perfect to receive the world at home.
Now, with the e-mail and internet, it is easier than ever to contact or to screen. I have never made an unpleasant experience as host or guest.