As someone who does experience and has experienced numerous hallucinations in the form of both voices and visions, I can say it is impossible to draw any line between sanity and insanity. There really is no definite way to define if someone is "psychotic". Even if someone hallucinates in the middle of the day on a daily basis, they are not always "insane" as they could be functioning perfectly fine. Someone could hallucinate several times or more during a typical day and function alright. I have been like that at times, so when you think about it, drawing the line becomes difficult and maybe it is best to not draw distinct lines between "crazy" and "sane"