I got an invitation to an open house in my neighborhood about a decade ago and I went. I was curious to see what another floor plan in my neighborhood looked like and I was invited via a postcard or something. (I can’t remember; so long ago!) It never occurred to me it might be considered nosy. Open house means open house. I’ve lived in my current house since 2000 and it’s our first house so I have yet to have a house-selling experience. I will someday though because my husband and I agree we don’t want to stay here when our kids have all moved out. So I’m reading this thread with great interest.
If I was in the market to buy a house, I'd attend an open house if I had already looked it up online and liked what I saw. I have a super terrible time visualizing how big a space actually is (feet, yards, etc. mean nothing to me) until I see it in person.