While growing up, I observed this unique phenomenon that I've been having difficulties explaining even as an adult.
..
..
As a child, we had this color TV in our living room. This television could pick whatever movie our closest neighbor is viewing on their VCD player. Simply put: we could watch our neighbor's movie in our room, on our TV!
..
..
The most shocking part of all this was a neighbor who lived like three flats away from us. Could you guys believe we could view their Famicom game on our television, right in our living room? Like whatever is happening on their TV is being projected live on to our own TV. Don't know if any of you here have had this experience.
..
All we had to do is flick through a couple of TV channels (no decoder, no external antenna) and adjust the antenna popping out of the back of our old Panasonic television and there you have it! A live movie from Baba Chibuike's house.
..
..
It's quite strange and interesting at the same time. I honestly have no idea why it happens but trust me, we've watched a lot of cool movies back in the days without having to worry about VCD rentals.

meobizy:
Back in the 90s, which I believe you're typing about — here it continued into the early 2000s, devices existed which one could connect to TVs to transmit radio frequencies of whatever media was being played. This existed because the technology of passing signals through wires which ran through walls was either unavailable, too much of a hassle or expensive at the time. People settled for these mini antennas of sort in homes with multiple televisions. A positive was children of the house being able to view content straight from living rooms without interrupting parents' business oriented visitors. One disadvantage (an advantage to neighbors living in poverty) was the signal being able to output past a specific zone. For higher end devices, a neighbor eight houses down could receive set signals by tuning their TV to match the output frequency. For base models, one could receive the signal either one or two houses away. In your case I'm sure your TV discreetly auto tuned for programs hence your family receiving the channels by turning on the TV.

It was in 2000's. The shocking thing was that our TV or neighbor's had no fancy signal receiving gadgets. simply put, we had no antenna and neither did our neighbors.
.
How do I know? It was an estate and on that street, almost everybody knew everybody.

.
I have limited knowledge about the technology you're referring to, but I'm glad someone could relate.