take 2 mickey mouse heads and throw them on the ground, when the ghost sees it he/she will run into a room giving you the chance to vacuum it
wear your anti-ghost armor and get the specter deflector
when you see a ghost dancing in the hallway, now is the good time to hide, it is his/her silent mating call
make sure that you have a pet micropachycephalosaurus as ghosts have hippopotomonstrosesquippedali ophobia
ghosts are afraid of blue, so show them facebook
when you see a ghost, try to pour water on them as they are probably using invisible spray