There is a commonly used electronic device called a transistor. Among its parts are a "source" and a "drain".
Funnily enough, at least sixteen different people have received patents in which they described the transistor source as a "sauce" rather than a "source".
After finding one of those patents by accident, I decided to look for another, more famous misspelling. Sure enough, two people have received patents related to "nucular" power plants.
I can imagine making this kind of mistake in an email or blog post. But to make it in your final patent application - and then to have the patent office approve it - is just incredible.