I'm currently listening to a Radio 4 broadcast about a medium (i.e. someone who supposedly communicates with the dead for profit) who, later in his life, declared that he was a fraund and he also exposed many of those around him as frauds. Part of the podcast refers to some people who were exposed as fraudsters but whose clients were so taken in by them that they considered the overwhelming hard evidence to be fake. The moral of the story is that some people simply have such a belief that overrides evidence and critical analysis. This phenomenon extends beyond just wanting to hear from Aunt Fanny as to how she is doing 'up there', of course.