Yes, that happened to us one day leaving MIA. The approach controller cleared us to 6,000 ft and the FO read it back and reset our altitude to 6,000. I said call and verify we are cleared to 6,000 and he said yes he cleared us to 6,000. I made him call and verify as I was shallowing my climb not to pass 5,000 ft as is our normal altitude and he said negative you are cleared to 5,000. He must have been doing arrivals and said 6,000 without realizing he said it. Helping each other keep it safe when someone errs is much nicer than filing a report.