Before you call the Sangoma you need to know that many things other than witchcraft and mental illness can cause hallucinations.
It is true that mental illness can cause hallucinations however the hallucinations due to mental illness are rarely ever visual. Psychotic conditions like schizophrenia usually involve auditory hallucinations. Auditory hallucinations means that you hear voices that are not there.
Seeing things or visual hallucinations where you see and hear well formed people, objects or animals is not a common symptom of schizophrenia. Visual hallucinations are usually a side effect of medications. They can also be due to intoxication and/or withdrawal from illicit drugs.
When you are not a user of illicit drugs and you start seeing things it's very important to think hard about any new medications or recent changes to your medications. Also think about any herbal remedies you may be using. If a doctor does not take a good history of your current medications you might end up being refered to psychiatrists and risk being put on anti-psychotics when you do not need them. Take a list of all your medications to the doctor and ask the doctor to check if any of the medications can cause hallucinations as a side effect. If you are asthmatic and recently had an asthma attack ask your doctor if they gave you medications called steroids to help open up your airways. Steroids are known to cause hallucinations in some people. Stress and lack of adequate sleep might also cause hallucinations therefore think about these issues to discuss with the doctor. Also think about new foods you have eaten recently or beverages you may have taken with possible hallucinogens.
In the unlikely case that you may be developing a mental health problem do not feel defeated. Psychiatrists can work with you to control whatever condition you are developing. Remember the brain is an organ like any other part of the body and if it is unwell we need to treat it just like we treat a cough or a broken bone. Mental health problems can be well controlled by psychiatrists so do not be ashamed to ask for help.
If you do go to the Sangoma try not to accept any remedies you have to eat or drink because these might be toxic or may cause you to see things more.