I would like to create an NPC who has got visions and gives out oracles and riddles as hints to the future. But I would like her to not be able to control this feature voluntarily or to see clearly what will happen. The feature/feat/template could be divine, psionic or magical, though not trained. The NPC has to be human, though outsider heritage is possible.

I know, I could just make it up, but are there existing rules I could base it on?