lightning conductor  
noun [ C ] UK uk/ˈlaɪt.nɪŋ kənˌdʌk.tər/ us/ˈlaɪt.nɪŋ kənˌdʌk.tɚ/ (also mainly US lightning rod)
  (METAL STRIP)     
  避雷针
a strip of metal, going from the highest point of a building to the ground, that prevents lightning from damaging the building by taking the electricity to the ground before it can reach a dangerous level
   (FOR CRITICISM)      
 替罪羊,代人受过者;引火烧身的人(或事)
someone or something that takes all the blame or criticism in a situation, although other people or things are responsible too
  In a harsh economic climate, pay rises for politicians have become a lightning conductor for criticism. 在经济状况十分严峻的情况下,给政客涨工资这一举措便成了众矢之的。