May not be creepy to you, but this shit terrified me at the time.
When I was about twelve or thirteen, both my parents worked, as they still do. At that time, I'd have the house to myself until half-past three in the afternoon. We didn't have a landline at the time, only cellphones.
For maybe a month or two, here and there, I'd hear a ringing noise for a few minutes at a time. It sounded a lot like a landline - and bear I'm mind that our closest neighbor was about half a mile away.
The creepiest account of this happening was around 1-3 in the morning. I had just laid down to go to bed.. and it rang. It sounded like it was right inside my room, right by my head. As far as I know, it didn't stop until I fell asleep, and that was the last time I can remember it happening.