Law enforcement sources tell us Stanley was arrested Monday night in Indiana based on warrants for her arrest out of Tennessee. She was wanted on seven counts of felony criminal simulation -- basically, cop speak for creating fraudulent coupons, we're told.

Sources say police in Clarksville, TN were alerted to a coupon scam Mellie was allegedly involved in back in November. We're told she tried making a $2,412 purchase at a Toy "R" Us there, but fled suddenly. Sources tell us she had 7 coupons that were somehow made to seem redeemable for $300 each. The cashier was suspicious and called cops.

Our police sources tell us the TN authorities were already on Mellie's tail for similar crimes in at least 4 other states. We're told police believe Mellie is part of an organized theft ring that makes counterfeit coupons, which they then use to buy gift cards to make illegal purchases at a variety of stores.

We broke the story ... she was arrested in Kentucky for a very similar alleged incident back in December ... allegedly trying to make off with $18k worth of Toys "R" Us gear.