Amber – Theme dreams are quite common.
Part of the action of dreams is to do your ‘housework’ to keep your house – you – clean. And what causes such long term themes is that the situation that needs attending to have not be done. They can carry on for a life time is not dealt with. A woman in her 50s told me that she had been troubled since childhood by a recurring nightmare. She would be walking down a street she’d known as a child, and pass some railings. There was nothing obviously awful in the dream, yet she always woke up crying and fearful. When she was in her early 40s she told her sister about the dream. Her sister said that when the dreamer was about three they’d both been attacked by a group of boys while near those railings. To stop them, the sister had said not to hurt them because their mother was dead. At this the boys had left them alone, but the dreamer had been badly shocked.
The nightmare stopped as soon as she learnt about the childhood incident from her sister. This suggests that her troublesome dreams were an attempt to make her aware of a part of her past that held unconscious pain or fear.
The ghost and devils are a recognised part of early childhood fears put into the images of demons and haunting. But to understand why you are troubled by them I think it might help if you read http://dreamhawk.com/dream-encyclopedia/what-we-need-to-remember-about-dreaming/
As it says in The New Dream Dictionary - In the world of dreams our most intimate fears and longings are given an exterior life of their own in the form of the people, objects and places of our dream. Therefore our sexual drive may be shown as a person and how we relate to them; or given shape and colour as an object; or given mood as a scene, something that haunts our memory shown as a ghost or demon. Our feeling of ambition might thus be portrayed as a business person in our dream - our changing emotions as the sea or a river; while the present relationship we have with our ambition or emotions is expressed in the events or plot of the dream.