set a thief to catch a thief
用贼去捉贼
口语·比喻用内行抓内行
英文释义
to use a person with questionable character or expertise to apprehend or expose another person with similar qualities or skills
例句
They hired a former hacker to fix the security system—set a thief to catch a thief.
典故来源
源自古代谚语，认为只有同样狡猾或懂行的人才能识破并抓住同类，常见于侦探或犯罪语境。