This is AC (BX) cable. It was/is VERY common in the states, especially in commercial settings. The AL "wire" is the bond strip. It helps keep a continuous ground path in the cable sheath.
It is meant to be wrapped back on the sheathing before the cable is put into a connector. It is NOT a ground. It DOES NOT get terminated anywhere on any device or ground bar.
Please post back and let us know how it turns out....