Old wiring to new wiring
 

My house is from 1937 they have updated the fuse box with circuitbreakers but the wiring is still old.

I was wondering how to wire new wire to old wiring for an outlet. There are the main lead has 3 wires black, white, and kinda white red looking wire. The casing or the wire is metal.

What kinda of new wiring do i need. What is the third wire kinda white wire for?

posting a picture could help in getting feedback

old wiring
 

I will post a pic when i get home today

The kinda' red wire may have been there so a switch can control one half of the outlet (receptacle) unit.

It is r4ecommended to run a new cable for the new receptacles, etc. all the way back to the panel. While the metal sheath around the existing cables can be a grounding conductor, it may or may not be sufficient and some additional examination and tests would be needed to determinine if it is.