Here's a new one, or maybe not.
Suddenly my fuel gauge was showing near empty. I added 100 bucks but the needle only came up a little. Hole in float? I noticed the chain for my fuel cap was gone. Where? Yep, it had fallen down the filler tube and wrapped itself around the float of the sending unit in my fuel tank preventing it from floating. I had to cut a hole in my wood flooring to access the handhole above the tank. Had a new sending unit ready to go. Put a new sending unit in. All good again.