Multiple breakers can turn off power on same line
I just found out that more than 1 circuit breaker can control same line. If you turn off the breaker connected to wire and power goes off, on the same time if you turn off another breaker which is not connected to previos line, power goes off again. If you change wire to another breaker, none of the light and/ or outlets works but the wire is carring power from breaker. It is an old circuit breaker box and old wiring.
Can anyone help please?
Thank you.