For me, depends solely upon who it is.
My one sister has full access to my home and anything in it, if she ever needs. She has her own key to my home, as well...n it'll always be that way. Same for her regarding me.
However, neither of us just "walk on in"...we have a routine, knock AS we enter...hollering "it's only me". We call before we come over, again, neither of us really care to be disrupted if not in mood..so we mutually respect that, though neither of us are "put out" if the other should just pop on in. Once in, its a free for all...don't matter...help yourself..lol.
Any of my other siblings can stay away, for all I care, and they do. Never invite them into my home, let alone my life.

As for anyone else, though..No way. Not heard of.

Shangrala