barking up the wrong tree
US /ˈbɑːrkɪŋ ʌp ðə rɔŋ triː/
UK /ˈbɑːrkɪŋ ʌp ðə rɔŋ triː/

1.
找錯了對象, 弄錯了
to be pursuing a mistaken course of action or to have a wrong idea about something
:
•
If you think I stole your pen, you're barking up the wrong tree; I haven't seen it.
如果你認為我偷了你的筆,那你就是找錯了對象;我沒見過它。
•
The police were barking up the wrong tree when they suspected the innocent man.
警方懷疑無辜男子,是找錯了對象。