Most of the wiring in my house seems to be bx cable. Can I use the updated wire with 3 wires and how do you hook up three wires to the electrical box. My breakers have the back wire going to the breaker and the other going to the bar. Can I put in a breaker that accepts two wires and connect the ground to the bar?

Thanks for you help and time.

Can you provide more detail as to what your trying to accomplish? It would help with giving a better answer.

What is updated wire with 3 wires?

What does
My breakers have the back wire going to the breaker and the other going to the bar
Mean?

What will this be used for: breaker that accepts two wire?