As late as 1978 in New Brunswick, Canada although we in town had a private line, I had friends 15 miles out in the country who had party lines. I was always reminded to watch what I said.
As teens my stepfather took us to his telephone company switching room and let us listen to a minute or so of our neighbor’s phone calls by connecting a portable phone with alligator clips, he evidently knew which lines were which, after that we assumed that he monitored all of our own phone calls.
My aunt had a party line in rural MI in the early eighties. When I was a child and I would visit, she would always re-teach me the rules about her phone and about how party lines were not necessarily private, but we must try to follow the rules and not interfere on another person’s call.
I never knew any another person who had a party line.
She lived so far out in the country, though. All of her family lived hours away. Whenever I was there, I didn’t notice the phone ringing that much.
Now, with free long distance and cellphones, our lives are constantly interrupted by the phone.
A friend of mine owned a property in rural Ontario and had a party line there in the late 1980s. The telcos recycled the technology and packaged it as “distinctive ring” where an customer could have multiple phone numbers on a single line.