What you need:
Focus

1) You need to relax. Get into a comfortable position.
2) Meditate. This helps find voices in your head.
3) Open up your mind. Let spirits know you're there.

If you dont see/hear voices in your head, try again. They might just be shy, most ghosts are. Don't forget to keep the conversation going! Ask them their gender, name, age, whatever you want! Now you can talk to ghosts!