I admit that my neighborhood is not the nicest in Seoul. Nope, I don't live in 살기 좋은 영등포. And the fixed-line phone service here has always been pretty weak. I frequently can overhear other people's calls in the middle of my calls and occasionally even have words with the 아줌마 on the other line who has somehow gotten merged into my line.
I don't believe nicer neighborhoods suffer from this problem as much. At any rate, when I saw the rat's nest that is my and my neighbors' phone connection, I suddenly understood how this line crossing could happen.
There doesn't seem to have been much care invested in that wiring job.
No wonder everyone loves cell phones around here. That way the people who aren't on the call can only overhear one
side of the conversation.