杯弓蛇影bēigōng-shéyǐng

应劭《风俗通义·怪神第九》记载，应郴请杜宣饮酒，挂在墙上的弓映在酒杯里，杜宣以为杯中有蛇，疑心中蛇毒而生病。后用“杯弓蛇影”比喻疑神疑鬼，妄自惊扰

英extremely suspicious;have imaginary fears as one who mistakes the reflection of a bow in the wine cup for the shadow of a snake