In itself, I globally don't mind having people in my house, whatever I know them or not, as long as they globally don't generate any trouble and mind their own business. The thing I can't stand is the kind of social interaction you are more or less automatically forced to endure when you are sharing physical space with someone. Especially when it's unexpected.
For example, a few months ago an elderly man I didn't know knocked at my door. He was my next door neighbour and he had accidentally locked himself out of his own house. He stayed for half an hour in my kitchen while waiting for the locksmith. I had no idea what to do, and I was extremely nervous and stressed. On the other hand, if the repairman is just in the next room repairing something, or my landlord comes in a few minutes to collect the rent at the time I was expecting him, I don't mind it at all.
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ouroboros
A bit obsessed with vocabulary, semantics and using the right words. Sorry if it is a concern. It's the way I think, I am not hair-splitting or attacking you.