get (one's) wires crossed

1. Of oneself, to be or become confused, mistaken, or mentally disordered (about something). An allusion to telephone lines being wrongly connected and thus disrupting calls. I'm sorry for bringing you the wrong order, sir, I've been getting my wires crossed all day! Wow, it sounds like you really got your wires crossed about how to process that shipment! Wait, I was supposed to print the handouts for the presentation? Aw man, I got my wires crossed, I guess.

2. Of two or more people, to have a miscommunication between one another, resulting in a mistake or misunderstanding. I'm sorry about all the confusion regarding the contract, Bob—it looks like we got our wires crossed somehow. I think Mary and Robert's fight is really just the because they got their wires crossed. My mom and I got our wires crossed, and now there's no one here to babysit the kids.

get your wires crossed

BRITISH, AMERICAN or

get your lines crossed

BRITISH

If you get your wires crossed or get your lines crossed, you are mistaken about what someone else means. She looked confused at what he said and he began to wonder if he'd gotten his wires crossed. He appeared to get his lines crossed. `What part of America are you from?' he asked. `Sweden,' came the reply. Note: You can also use the noun crossed wires to refer to an occasion when there is confusion about what someone means. After a few minutes of crossed wires and confusion, it transpires Cerys has mistaken me for someone she knows. Note: People used to say they had a crossed line when their phone call was connected wrongly and they could hear someone else's conversation.

get your wires (or lines) crossed

have a misunderstanding.

Wires being crossed originally referred to a faulty telephone connection (‘a crossed line’), which resulted in another call or calls being heard.

get your ˈlines/ˈwires crossed

have crossed ˈlines/ˈwires

(informal) misunderstand each other: I think we’ve got our lines crossed somewhere. I said Venice, not Vienna. ♢ We must have got crossed wires. I thought you were going to drive, not me.

This refers to telephone wires/lines that are not connected properly.