Spelling mistakes in published works are much more common than many people expect.
You only have to ask a professional proofreader to read over a sample chapter to stand a good chance of finding one or two.
How does this happen? An over-reliance on spell checkers is part of the problem.
For example, there are lots of words that sound the same but have different meanings (technically called Phonological ambiguity) so it’s easy to use the wrong word and have it go undetected. There are lots of them including: brake and break, bear and bare, sail and sale and the old favourites like there and their, to, too and two and even by, bye and buy.
If you’d like to take a look at common misspellings then take a look at