This happened in the late 80's. I had gone to visit my father for the Christmas holidays, and during my visit, he gave up his bedroom for me so that I could have privacy. He had this radio in his room that I liked to listen to before going to sleep, so when I was ready to return home, he asked if I wanted to take the radio with me, since he had others. This was a regular, unremarkable boom box type of radio. So I brought the radio home with me.
One night I decided to turn it on as I prepared supper but couldn't find any music. I turned the dial, growing frustrated because I wasn't picking anything up. Finally I heard something and I raised the volume. What I was hearing sounded like a man's voice talking in an echoing room, and it sounded like he was chanting. I could also hear the voices of a lot of people, and it sounded like they were moaning or lamenting. I couldn't make out words, but it creeped me out, so I rapidly turned the tuner dial to find something else. But all that I could pick up was what sounded like some kind of ritual being done. All I could pick up was the guy chanting, and the people in the background making these lamenting sounds.
I turned the tuning dial until I reached the end of the range, and could not pick up anything else. So I turned off the radio and put it away in a closet. One of my more creepier experiences.