The poltergeist and the cursed book from where it spawns.

A book found in woodland mansions. Any weapon, tool, potion, armour (all pieces worn would be affected) projectile or stick could recieve this curse. The curse could be applied via an anvil. Holding anything with that curse could cause it to be yanked out of your hand and start moving about on its own, in reality this is the work of an almost completely invisible poltergeist. Fortunately this curse is temporary as poltergeists could disappear after a while. Upon the death of this poltergeist your items would drop partially damaged. However while the poltergeist is active it might decide to attack you (only in easy, normal and hard), so watch out or if holding a tool break something (though not too often, perhaps as often as an enderman? I think this would be cool as you could have walking about suits of armour or a floating sword even in peaceful, which could be useful in map making and would make for an extra challenge in survival when exploring a woodland mansion.