Baseball Wives Sex Toy Meltdown?

During a recent filming, Anna Benson -- the wife of former Mets pitcher Kris Benson -- got into it with Cheri Knoblauch -- wife of former Yankee second baseman Chuck Knoblauch.

Anna got creative, pulled out a stun gun and set it on a table in front of her in a threatening manner, then produced a 12-inch sex toy from her purse and started swinging ... which raises the question, Why such a big purse?

Sources connected with the show tell TMZ ... some of the staffers are now threatening to quit, because they can't handle Anna's insane behavior.