The continued belief in the reality of ghosts despite their unscientific nature can be reasoned down to a person’s social class.
Using Foucault’s philosophy we can use types knowledges to see the power structures within society and how they control us. Those who are unhappy within society such as the working classes are in position to critique society and thus see these structures.
By believing in the paranormal, one is making a choice to accept a knowledge outside of the ones deemed acceptable by society and thus unmasking the structure of what is and is not acceptable.