Dictionary / Vocabulary / 人違い
ひとちがい
mistaking one person for another; (case of) mistaken identity
common word
調べてみたら人違いだった。
When I inquired I found that it was the wrong person.
この映画は貧しい女性が、列車事故による混乱で富豪の令嬢と人違いされてしまう物語です。
This movie is about a poor girl who gets mistaken for the daughter of a rich man in the confusion following a train crash.
人違いだと思います。
I think you've mistaken me for someone else.