What it says on the title. Mine was when I was 12 and I lived in a very haunted house which had some weird activity going on, like things moving out of place and pets freaking out. I was sitting in the computer, alone in the house, and suddenly I see a shadowy figure on the screen, just some meters away behind me, thinking was my mom I turned around and there was nothing, but the room had turned extremely cold suddenly. There was nothing behind me that could have been this shadow.
I mean, it wasn’t like I was looking at some horrific ghoul or something. She was pretty. I’m not sure if I witnessed a spirit, so much as possibly a non-gruesome teleporter malfunction.