There have been many recent reports (like this) of UFO sightings over Lake Michigan and Lake Erie—triangular lights, hovering, speeding off, etc.

For the serious Great Lakes night viewer, the International Space Station (ISS) actually does pass over the lakes once in a while and is a bright, bright object in the night sky. The next viewings of the ISS will be this weekend, Saturday and Sunday nights (clouds permitting). For those interested in sightings, NASA offers a schedule applet at spaceflight.nasa.gov/realdata/sightings/. The ISS won't appear over the Lakes again for several months...