Like Tishie and AAAAA I live in a rural area, it's not uncommon for family and friends to just walk into my house, I hardly ever knock when going to family or friend's house I just walk right in and let them know I"m there. I think someone mentioned you know a stranger is at the door when you hear a knock.

As for the fridge, that depends on who's doing it, I don't mind for close family and friends but if it's someone I hardly know getting in my fridge I find it a bit unnerving...I would at least appreciate them to ask or be offered first...

It's really common around here for family and friend's to leave a set of keys in someone else's possieon when they are going to be out of town and have them check on the house and invite them to make themsevles feel like home.

I find it interesting the diffrent replies and how they correlate between a rural or suburban area