In another of the screwy decisions made when the former owners of the house finished the basement, the light in the closet under the stairs (you know, so Harry can read in there) is just a fixture with an electric cord stapled to the wall that runs out the corner of the door and plugs into an extension cord that's plugged in behind the couch.
The light's cord short circuited at some point, and melted in half. The half still connected to the extension cord, which was still plugged in behind the couch, was getting wet thanks to last night's flooding.
Most of the wiring looks sound, but I can't help but wonder if there are any other surprises like this lurking in corners. I'm thinking one of the things I need to do soon is have a licensed electrician go through the house.