This normally occurs when text has been copied from a different program like Word and pasted into WordPress which causes the text to retain the original formatting.

Fix:
  1. Copy the text that is displaying incorrectly from WordPress and paste it into a plain text editor like notepad (not Word) This will strip out any special formatting, etc..
  2. Copy and paste the text from your text editor back into WordPress
  3. In WordPress, re-apply the formatting for bold, Italics, colors etc. 
  4. Save
  5. View the page and the text should now display correctly.