AceShowbiz - A Lady GaGa look-a-like caused chaos in Miami, Florida on Sunday, March 27, fooling fans, photographers and shop assistants as she toured town with a massive security detail. The petite blonde traveled in a motorcade of four SUVs with 10 security guards and she went to a French Connection store in South Beach on the day of the pop star's 25th birthday on Monday, March 28.

A source tells the New York Post, "Salespeople flocked to assist her, even helping her try on clothes for 30 minutes. She was swarmed by fans screaming 'Happy Birthday!' " A press officer for a Guess shop in the area even released a statement about the visit, revealing, "The crowd was getting so out of control that security needed to shut down the store so Lady GaGa could browse..."

But the visitor has since been exposed as a fake - Lady GaGa was actually celebrating her birthday in Las Vegas on Sunday and her stylist Nicola Formichetti confirmed the woman in the pictures is not GaGa, writing on her Twitter.com page, "Thats (sic) not her!!"