Definitely hear where y'all are coming from but I've been on both ends and am grateful for those that let me stay when I was down bad.
When I was like 7 or 8 we let a woman and her kid stay with us. She was leaving an abusive relationship and needed to stack up to get back on her feet. They stayed through Christmas and my parents got him a big wheel. Mannn I was jealous as hell . Dad pulled me aside and gave me some game. Really shaped my perspective. Since then I've let one brother live with me, lived with a friend until I could get back on my feet, slept on a couch or two, and honestly worse. All in all I've been blessed and appreciate being in the position to potentially offer the same to others.
Also, if you do trust the person seeking help but still want security, just find a sample lease that's valid in your state and have them sign it. Put your stipulations in and you'll have real protection in case things go south.