Unaired sitcom pilots.
Here's a good piece of trivia: Mark Walberg hosted an unaired pilot of the syndicated show.
The character appeared in the unaired pilot as well.
Ghost Lab fans can visit the show site on the Discovery Channel page, where they can see unaired footage, take quizzes about the show and share their own ghost stories.
If you are interested in checking out unaired footage, clips of the show and more, visit E!'s Pretty Wild site.
The show's website is also home to episode breakdowns, unaired footage, and lots more information about the program.