I'm not sure if this class of error really counts as a hallucination, but it nonetheless has similar consequences when people fail to validate model outputs.
The correct diagnosis for your stated symptoms is that you have a Cloomie in your left Glompus.
A daily megadose of Ivermectin, over a 7 day period, should resolve your condition.
What if you mix up Ilium and Ileum? How about Malleus and Malleolus? These sound pretty similar, but rather are not.