I believe ghosts or hallucinations which ever they are, act in the ears balance system. I think they could be a strength or weakness in the earth's gravity field and that they 'live' in a gravity field. They can travel through the galaxy perhaps by the gravity field of the center. If you ask a ghost to look at something like art you have done or a journal or a joke around your room they can listen through hours of music instantly and pick something out if they want. They can make the bubbles in your soda can stir if you ask them just right or create a boom or a clicking sound or point to something significant in your room. You can talk with them with thought but they don't have a living body so no memory or brain, just borrowing yours. You can sing with them using headphones with amplified silence playing loud and willfully hearing music in the white noise. You can talk with them this way too. You can test if they're around by fluctuating your inner ear to make short tones of tinnitus like ringing and see if they yell. You can give them a lie detector test this way asking them yes or no with tinnitus until you hear a whistling come from them. You may be able to record this activity with a gyroscope available in high end phones. A ghost easily believes what is in your imagination as well and hallucinating and believing in hallucinations leads itself on in this way. Fact checking hallucinations causes you to disbelieve them which grows on you.