Because the price of silver would shock you and copper is much less expensive.
For wiring, we only use copper and silver. The most common conductor is copper. Almost all wires use copper as a conductor.
Copper piping and wiring and not interchangable.
Electrical wiring.
Electric wiring
The main use is in electrical wiring.
Copper has a myriad of different uses, but the use that first pops up in my mind is its use for electrical wiring.
Its used as wiring, and composes most of the penny
Copper is an excellent conductor of electricity. Among metals it is second only o silver, which is too expensive for practical use in wiring. Copper is also extremely ductile, meaning it can be easily drawn into wires without breaking.
copper is in every thing, from electrical wiring in your house to electric motors that you use in your kitchen.
Most do have copper in the wiring.
If you are asking can you connect aluminum wiring to copper wiring, the answer is yes. With one provision. You must cover the connection with a special compound prior to putting on the wire nuts. This compound is available at Lowe's and Home Depot and Ace.
Copper is almost always used in car wiring.