Dua for protection

I have a friend who reverted recently. He's a native African who's been separated from his mother for a long time. She's said to have this "calling" to be a "sangoma" which in his terms is a medium for communication with spirits. He says the "spirits" now worry him and he sees them. What should he do? Is this even possible since we cannot see the jinn? And if its not jinn then it can be nothing else right? But his mind is playing tricks on him right? I did advise Ayatul kursi and Suratul naas.