I believe in demonic principalities, not ghosts.
Both my aunts and great aunts were pretty involved in what we'll call spiritualism-- seeking the spirits of the dead in various ways. My grandmother saw that what her sisters were doing was messing with them (spiritually, emotionally and psychologically) and knew that scripture (the Bible) speaks against such things pretty stongly, so she put her foot down. She raised my Mom, and my Mom raised me with an awareness from a young age about what scripture says about the spiritual realm, and the power the blood of Christ has over demonic presence. Unfortunately, my Mom's sisters fell prey to their desperation for control after my grandfather died when they were young, and set out to find him.
I think because I'm aware of these truths, I've already dealt with a lot of spiritual warfare in my short life. This topic has a funny way of following me around, and I've become kind of passionate about offering a usually unheard of viewpoint (which baffles me). Most of our society has been blinded and deceived by pop culture's explanation of the demonic: the departed souls of loved ones that just need to be heard or want revenge or what have you. It's a short path to self righteousness, and a belief that we can know all apart from God. Oh, and a sick way to terrify ourselves, which of course we need. ?
Just my take, I'm glad to talk details if anyone would like.