What does a Ghost mean in a dream?

A Ghost in a dream can represent:
Death
Change
Is someone from your past trying to give you a message?
Are you fearful about the ghosts from your past?  Things you've done or people you've done wrong too?  Do you need to find peace or closure with them?
Are you afraid of death and dying or fearful of what happens to us after we die?
Alternatively, ghosts can representative something that is no longer obtainable or within our reach.
Fear/haunting - Is something from your past following you? Are you literally being ‘haunted by your past'?
Shadow self -Are you a ghost of your former self?  Have you lost your way?
Ghosts may also symbolize a guilty conscience - do you have some left over guilt or repressed feelings regarding someone in your life that has passed on?  Is there unfinished business?

See also 'Dead' and 'Death/Dying'