Okay I've sat on this for a while but I'll tell you what happened to me. Before I start I want to say, I don't believe in ghosts and that but.. this genuinely happened and I don't know how to explain it.
When I was around 15 and learning how to record music at home, I thought it would be cool to record the sound of rain and use it within a song (corny I know). So I had this little dictaphone, it was raining and I was going to sleep. I left the dictaphone recording the rain by my window and went to bed. My intention was to transfer the rain recording onto a shitty 4 track recorder I had.
When I played the rain back the next day, I heard a blip, like someone talking quickly. The dictaphone had a little button that let you play things at half speed, so I flicked it. What I heard when I listened again was an old lady saying "Hello..?".
I was pretty shaken up. However I tried it again that night to see what would happen. I listened back to it and again I heard a blip. I slowed it down and heard an old lady saying " Put me down!". I didn't try it again.
Some months later I was home alone (at 15.. I know) because my parents were visiting family abroad and one night I heard choking coming from the bathroom. I have never been so scared in my life, I didn't go and check it out. I just pulled the covers over my head and shook.
That house was over 100 years old and a priest uses to live in it. That's all I know.