Even that is hard since there are many words where a mispelling is a valid different word.

As a copyeditor/proofreader, the number of times over the years I've had to fix the low-quality (i.e, wrong) suggestions is quite large. ("he had a small plague on his desk" remains a favorite.)

   I have a spelling checker    
   It came with my PC   
   It highlights for my review    
   Mistakes I cannot sea.    
   I ran this poem thru it   
   I'm sure your pleased to no   
   Its letter perfect in it's weigh   
   My checker told me sew.

https://www.thoughtco.com/spell-checker-poem-by-mark-eckman-...

"He looked in the [car's] grove department" is still my favorite.

One of my favourites was 'rouge elephant'.

Having written a spellcheck, maybe 20 years ago for school, this is accurate.