Definition
Used to express disbelief about something heard, often because it seems highly improbable or unexpected.
我听错了吧（表示难以置信）
She said she's going to quit her job? I must be hearing things.
她说她要辞职？我一定听错了。
You're saying he actually agreed? I must be hearing things.
你说他真的同意了？我一定听错了。
They're saying they'll provide all items for free? I must be hearing things.
他们说免费提供所有物品？我一定听错了。