I used the Internet to look up some Nancy Drew ghostwriters from the Supermystery series.
There is no information on Jack Hagee (author of Supermystery 36). Good, now I don't have to update my review for that book.
Larry Mike Garmond co-wrote Supermystery 7. Information on him is scarce, besides for the fact that he wrote a monster series in 2001-2. He let his website's domain expire. I updated my review for this book to mention him and Peter Lerangis.
Peter Lerangis wrote Supermysteries 2, 3 and co-authored #7. His biggest project right now is the 39 Clues series, which is totally amazing. I'm tempted to go to a book signing if he does one near me. He's the most famous of all the authors on this list, and he received honors from First Lady Laura Bush, but probably not for his Baby-Sitters Club books.
Susan and Bill Albert seem to be a married couple. Susan wrote Nancy Drew Files 6 and 11. Susan and Bill wrote Nancy Drew Files 15, 22 and 29. I'm rather surprised that all those books have the same author, considering how different they are. Susan is still writing today; her newest book came out in March. I'm not sure if I want to redo my reviews for those books, just to mention who the ghostwriter is.
Tracey West wrote Supermystery 13. That was her first book ever. She's still writing, and she mostly does books for TV shows like Adventure Time and SpongeBob Squarepants.
Kekla Magoon wrote Nancy Drew Diaries 2. She has a new book called Shadows of Sherwood coming out in August. Her books mainly focus on the civil rights movement.
Kate Angelella claims she's an editor, not an author. She edited Girl Detective #30. A co-worker named Jessica Burkhart says that Kate wrote Nancy Drew Detective #42. (She even includes instructions on how to get your book signed by Kate, but that was five years ago at this point, so I wouldn't recommend it.)
George Edward Stanley is now deceased, but he taught at a university in Lawton, Oklahoma.
There are a number of authors for the original series who are probably still alive, but I did not look them up. Maybe I'll do that later!