Applenut Pie
This pie is made from special apples and nuts; which is to say, ones used in certain rituals for divinatory purposes on Halloween night. Once the rituals are done the apples and nuts are baked into a pie, which then serves as a powerful aid to spiritualism and voluntary possession. Whoever eats a slice of Applenut Pie will find that she has become incredibly sensitive to the spirit world; a spirit may possess the subject automatically if she does not resist, and ghosts and ethereal entities are likewise automatically audible to the subject. The effects usually only last about ten minutes, and eating an entire pie will almost certainly render the eater unconscious after about an hour or so.
This item is generally considered to be white magic (or at worst, very light grey), as there is no coercion involved, the possession is of limited duration, and there are no permanent side effects. About the only problematic issue is the entire ‘summoning of ghosts’ thing itself; but if that is not considered to be pernicious, then neither will be eating a slice of Applenut Pie. Also, note that there are any number of Applenut Pie recipes that ‘work,’ in this context. In fact, there are occultists who argue that a pie is not even, strictly speaking, necessary; simply eating enough of the apples and nuts shoudl suffice to get the desired effect. The counter argument is, usually, that fruit pies are nice to eat, and there’s no rule that an edible magical ritual has to be, well, inedible. Besides, it seems a shame to let perfectly good ingredients go to waste.