here is an example: " Going to the moo n can be dangerou s!"
More detail please. Don’t leave us guessing.
It seems like a symptom of a cut & paste operation from an unusual source. It’s possible the spaces or other weird breaking characters exist invisibly in the document, application or website where you are copying from. Describe the steps you took to get to this point where you are seeing the spaces, otherwise the question is far too vague.
Many years ago I had a faulty keyboard that caused a problem just like to this. Have you tried a different keyboard?