If You're a Ghost, and You Know it

 To the Tune of: If You're Happy and you know it...

If you're a ghost and you know it,
Then say "Boo!"
If you're a ghost and you know it,
Then say "Boo!"
If you're a ghost and you know it,
And you really want to show it,
If you're a ghost and you know it,
Then say "Boo!"