Paper Mario: The Thousand-Year Door Glitches

Inside The Black
If you go to the Glitspit in Glitsville and you are the champion, go into the champions room and go threw the air vent that had the voices in them. Go threw the other side that leads to the owners office. Go out the door and (it only works somtimes) if it happens you'll run into the guy that is standing outside. You'll glitch out and you can walk insid the black part in the hallway.