Mispelled or Misspelled: How To spell?
The word Mispelled is misspelled against Misspelled, which is past tense of "Misspell"
Misspelled has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings mi & pelled which should not be misspelled with single 'S'
Wrong Spelling:  mi-s-pelled  Correct Spelling:  mi-ss-pelled 
Find more wrongly spelled words of Misspelled to spell it well.