Some communities are advertising the fact they are operating a green square in upstairs windows to indicate a vulnerable person lives there.  If the green square is changed for red, they need assistance and that could come from anyone who is just passing.

If you know anyone who is living alone and vulnerable perhaps you would dissuade them from this practice.  It’s a very bad idea and there are much better ways to support a community, not unlike the one that is now in place in Belton where you will always be speaking with your neighbours.