In May of 2007, the PawSox hosted a Latino Night. I have no evidence of this happening either before or after that date. There was dancing and music and Rhode Island's first all-Hispanic Boy Scout Troop (from Central Falls!).
I wish they would bring it back, because it was so cool. I get the feeling that it wasn't a well-attended thing so they didn't repeat it. I'm not implying xenophobia or anything.
The Pawtucket Red Sox should try this again. They should have done it last year, what with Carlos Maldonado and his posse. Maldonado was THE KING! Or 'El Rey', if you will. But yeah, they could probably throw something together this summer. I would seriously love that.
Click here to read a very dry and boring article about the effects of promotional events on baseball attendance.