I'm barking up the wrong tree

I'm barking up the wrong tree
 

Estoy intentando averiguar qué significado tiene esta frase: I'm barking up the wrong tree.
Quizás me podáis ayudar.
Gracias

It refers to a hunting dog barking at a tree thinking that what it is chasing is hiding in it, assuming it has the right tree.

It means to make a false assumption about something.

This is covered in the idiom section of tomisimo. (tocando la puerta
equivocada=knocking on the wrong door)

Puedes ver aquí.

Significa acudir a la persona (o instancia) equivocada.

Gracias a todos!!!
Thak you every body!!