If you see one, politely tell them that the apartment is now yours, and ask them to leave.
Also, avoid putting things like paintings or sculptures near the front entrance, and if you wish - place a mirror there.
Do I believe in ghosts? I don't know
Would you know that you're dead or would you want to accept that you're dead? If you can see living people, would you try to contact them in anyway you can? HE HE HE HE