I've donated to the Salvation Army, but I am unwilling to become a possible victim myself by taking even one stranger into my home.
Unfortunately I can see two ways this plan could go awry. One has already been discussed, and the other is psychos/perverts taking women and children into their homes.
In most cases the arrangements will probably be fine, but the potential for abuse in two directions looms large.
The sentiment behind the idea is admirable but practicality is another matter.