This automatically made me think about a few movies I have watched such as Revolver (2005) by Guy Ritchie, a psychological film in which the main character is fighting against his ego.
I have tried to combine the use of psychology of these movies with my own ideas to come up with this story that I am quite happy with and I would really appreciate your opinion or suggestions.
The executioner has mental disorder that pushed him to become an executioner, however after having executed an innocent man, he's been haunted by it and decides to isolate himself in the attic. He has been looking back at what he's been doing, he got this kind of awakening call, in which he became more conscious about what he's been doing.
Since then he's regretted killing the innocent man under the law's order. He used to spend his time thinking about it, his thoughts are haunted by it.
This developed anxiety in him.
Every time he wakes up, he finds the attic all messed up, broken lights, things moved around. He realises he's being pursued by the dead guy's ghost.
On day he's been running away from the ghost in the attic and accidentally steps on the box of matches which struck against the wooden floor and start a fire in the attic and causes the executioner's death, only to realise that there is no ghost, he's been sleepwalking and under the haunting thoughts of the dead man he started to hallucinate and create scenes about the ghost due to his anxiety.