Here is how you can referee for the WYSL recreation division. 

Visit www.Massref.net and sign up for a training course to become certified.  The entry level course for Referees is the "Referee Grade 8 Entry Level Course".  After completion, forward your credentials to referees@wysl.org and the ref coordinator will contact you with games to referee.

Any questions before you sign-up, contact referees@wysl.org