How? If we dont have evidence for it should we just conclude that it exists because our maths does not say it doesn't. Lets make witchcraft a part of medicine

How? If we dont have evidence for it should we just conclude that it exists because our maths does not say it doesn't. Lets make witchcraft a part of medicine then. A statistically significant part of the human population belives in it. Lets get that into a 4 semester course in a 6 year medical degree.