I agree with Will.  If you know deep down that they're not real, it's just a phobia.  Phobias are nothing special.  Just roll with it and do your best to let your intellect get the upper hand whenever it can.

I had an encounter with a ghost when I was about 10.

My grandmother came into my bedroom and woke me up. She said, "I'm just checking on you. Go back to sleep." Not surprising; she said stuff like this when she was visiting.

Next morning, I asked Mom and Dad why Grandma didn't stay the night. They asked, "What do you mean?" and I told them about her waking me up. "She wasn't here last night," Dad said. "You must've been dreaming.

An hour or so later, Dad got a call. His mom had died the night before.

Now, this was creepy to me. But, as I talked about it with Dad years later, he said, "It's not that surprising, Son. Your grandma hadn't been doing well." (She died of cancer.) "We'd been talking about her, and how she might not get a chance to see you kids again, in the days leading up to it, so it's no wonder you dreamed about her."

Now, up until that point, I was convinced I was awake, and Grandma had visited me. But it wasn't real.

Dad tells me I used to dream about all kinds of things. Once I was convinced bigfoot was after me, and I still have dreams where he can reach me on my invisible flying carpet. And don't let me get started on the whole Snap, Crackle, and Pop fiasco; they know what you are doing. They're worse than Santa Claws. They watch through the windows.

These are all vivid dreams.

The worst, though, was when I turned the corner in a new house, and saw our dog Freeway. He'd been dead for over a year. But he always sat a certain way, and there he was, out of the corner of my eye, sitting exactly that way; but when I turned, it was the shadow of a curtain. But I swear it was him. Just for an instant.

Our hopes and desires and fears all turn on us. It's not the supernatural; it's our own minds.

Me, the way I cope with it is, I really get into it. I love stories about UFOs, and ghosts, and so on. I visit the Bigfoot reasearch organisation website. I attend UFO conventions. It's fucking great. Not because I believe it, but because I don't. There is this side of humanity that demands something different, and all of this caters to that demand.

I can't tell you how to not be afraid of ghosts, except to remind you that in all the years of history, nobody's ever been harmed by a ghost. So the chances of one getting to you is pretty damned small. Meanwhile, enjoy your non-belief in ghosts, the same one that makes your heart race once in a while. Let yourself be scared, while at the same time recognizing there's nothing rational in the fear.

It's okay. Really.

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 I wouldn't worry about ghosts as there are real things to fear. When I was 18, I worked at a cemetery as a groundskeeper or if you'd like a gravedigger. In all the time I worked there the scariest thing I every saw was the funeral directors, talk about creepy. We even had to dig up old graves to relocate people after 50 or 60 years. Never were ghosts present, just old bones. Part of our job was to lower the casket into the grave and then fill it all in, such fun that was. No ghosts were ever seen wandering the cemetery by any of us. Plenty were seen by the drunk college students who showed up on weekends and around Halloween. 

My grandmother told me when I was little when I used to be afraid of such things as monsters under the bed and ghosts wandering in her old house it's the live ones you need to fear.

People who want to see ghosts will see them, not that they are real, but their mind is so convinced that they exist that they mistake a brain misfire and mix it with shadows and immagry stuck in their mind. Much like looking for shapes in the clouds.

Now just like any con, there are people and places that sell themselves as having ghosts and the proprietors of these places will con you whatever way they can because you are gullible into believing that ghosts exist.

One of the biggest cons purpitrated on the public is the "Amityville Horror" myth that an entire house was possessed by the devil. That myth started as a result of a REAL mass murder commited in that house. I am sure future owners knew the history of that house and because of the creapy real crime, some probibly saw what they wanted to see but again, only becuase of societal conditioning that the supernatural exists, combined with a brain delusion that causes that prediliction.

Ghosts do not exist. What does exist is the REAL electrochemical activity in the brain that can cause powerfull self delusions based on the gullibility of the person buying societial myths.

I too used to see "ghosts" and what "they" turned out to be is my own fears because of indoctrination and ignorance. Once I stared into the shadows and faced them, the ghosts never came back. The were never there in the first place, but my brain allowed me to see myth as fact, when it was a self delusion.

You can get over this by accepting the fact that your brain can and often does fill in the gaps subconciously without you conciously realizing it causing delusions that can seem real.

I have also had so called "outer body" experiances. That is just merely, once again, my brain in a very powerful dream state. I also had a couple cases where my dead grandmother and another time where my dead father stood at the end of my bed and talked to me.

AGAIN, merely powerfull dream states mixing with auditory and visual functions.

Even today, I have dreams, and I also leave my TV on and wake up realizing that the auditory input of the TV, mainly news can effect my dreams. I've woken out of dreams where I was in the middle of a war, because the story on the news was about a war. I've woken up out of dreams where I was having sex with a sexy woman, and woke up to see the "Girls Gone Wild" infomerical.

I know this is a bit long, but it is to insure you that you are not crazy and many here have had these "experiances" that seem real, but the only thing real about it is human nature and human psychology and the ability of the brain to fool itself subconciously. It is quite normal, but recognizing that it is merely a mind trick, will help you get over your fear.