eli5 how you could pick up a telephone and hear another conversation(not in the same house)

Question

when i was a kid you could pick up the landline and hit the call button and join whatever conversation was already happening. though i’m reading salems lot right now, and they mention picking up the phone and hearing a conversation from those i know are not in the same home. how did this work???

In: 0

Answer 1

Slightly related historical fact but early cell phones were analog and broadcast in the clear. With the right kind of scanner you could pick them up and hear the conversations.

Random phone calls are SO boring though.