The Andy Griffith Show S04 E21 The Shoplifters

"Nip it in the bud!"

Andy and Barney must find a shoplifter that's been hitting Ben Weaver's store, so Barney volunteers to dress up as a mannequin. He ends up accusing a little old lady and is ridiculed for another one of his famous blunders by everyone except Andy, who believes he might be onto something.