Medicine requires board exams.
https://www.americanbar.org/content/dam/aba/publications/mis...
http://www.slate.com/blogs/business_insider/2014/08/02/state...
In 2014, 60 apprentices took the bar exam (out of 83,963 total examinees). 17 passed.
Almost all states do require law school nowadays, and you don't have a prayer of getting reciprocity to practice in another state without it.
https://priceonomics.com/how-to-be-a-lawyer-without-going-to...