Get rid of any tombstones or urns you may have. You can use a cheat to delete them, or you could have your Sims to move out of the house they currently live in. Leave the tombstones and urns on the lot. Don't place them in your inventory. When you move out and move back in the tombstones and urns should be gone and no more ghosts should haunt you. You could also try selling the tombstones and urns. Basically, as long as you have these items on your lot, ghosts will continue to haunt your Sims.
Chat with our AI personalities
go to the graveyard after dark, you have to catch the actual ghosts(the ones that are like transparent sims, not the spirits that look like halloween ghosts)
I got it from helping Hugh fight ghosts. He gave it to to me.
No, you can't. Talking to ghosts was only introduced in the Sims 3. As a matter of fact, attempting to interact with ghosts in the Sims 2 may lead to the premature death of your Sim since they would be frightened to death of it. (Usually, it takes several scares in one night to have your Sim "expire")
Put them in your yard and every now and then they will come out.
Vampires, werewolves, plant Sim's, witches, warlocks, zombies, ghosts. I think that's it.