Think about this for a minute. You’re a beautiful young actress, born in Chicago, raised in London and when you open your mouth, the most delightful, sophisticated accent comes pouring out. You’re waiting for your big break in show business when the phone rings. One of the buzziest hit sitcoms on TV, FX’s “It’s Always Sunny in Philadelphia,” is calling. They want you for what could become a recurring role on the raunchy, outrageous gross-out fest. Sounds like a dream come true. THESY SURFACE AUDIO EXCERPT: "I think it was Charlie Chaplin who said, 'It doesn't matter how big the role is. Just be memorable.' And Margaret McPoyle is memorable." But… the producers want to paste a dark, heavy unibrow across that lovely forehead of yours. And your hair? Tied into pigtails. At least you’ll get to utter some real clever, coarse dialogue, right? Sorry, kid. Your character is mute. No words will be spoken. But you do get to make a rather salacious move with your tongue. What do you say? Thesy Surface said yes. Yes to Margaret McPoyle, the silly stuff of which TV legends are made on “It’s Always Sunny in Philadelphia.” For most people, this will be the first time you’ll have heard Thesy’s voice. Want to hear more? Check out her video blog at . And, oh yeah: the show returns to FX for its sixth season on Thursday, September 16 @ 10 p.m. (You can also catch up on episodes you missed on Comedy Central.) Mono-browed Margaret McPoyle — played by Thesy Surface —returns around Halloween. Thesy Surface • •