Articles about splice electrical wires
How to Splice Electrical Wires and the Ground: For projects where you are extending the wiring of an existing circuit then the additional wire size must match that of the circuit you are branching from or splicing. Electrical junction box splices can be made safely when you understand the method.
What is the Best Way to Splice Aluminum and Copper Electrical Wires? How to Splice Copper and Aluminum Electrical Wires.