Ariel Winter's Brother -- I'm Not Taking Sides ... BUT

Ariel Winter's brother filed court docs in the guardianship case in which he says he's not taking sides ... and then goes on to squarely take sides.

Jimmy Workman, an actor who famously appeared as Pugsley in "The Addams Family," says in his declaration -- obtained by TMZ -- he "NEVER" saw any physical or emotional abuse by his mother against Ariel. He concedes he saw "normal mother and daughter arguments and banter back and forth but nothing more."

Jimmy says the conflicts worsened when Ariel allegedly refused to break up with her boyfriend.

And then Jimmy says, "My position is not to take sides with anyone, but to get this family back to where it belongs." But the next sentence -- "I as well believe that Shanelle Gray is not the right person to have custody of my younger sister Ariel."