I think my son is becoming a shaman!?

I've been noticing that my son, over the past couple of months has been practising shamanism. He's been using incense all the time, I've found unknown "sacred" herbs in his room, he's been playing loud droning music to cover his chants, and on one occasion, seen him in a shamanic trance in his smokey room. How do I deter him from living the life of a shaman?