Almost all electrical wires these days are made of copper - which is why the price of copper is so high these days.
Lead in wires? I know the Romans used lead water pipes, but in all my years as an electrical engineer I've never heard of lead wires. I've heard the term "lead" (pronounced "leed") used in connection with wire, but I assume you're talking about the element that's a soft heavy metal used in fishing sinkers, and I've never heard of it being used in wires, nor have I ever seen any (and I've worked on devices made before the crash in 29.)
If you're talking about solder, yes. Up until recently, the solder used to fasten wires together was about half lead and half tin. But unless you're in the habit of chewing on wire splices, there's not really any danger from that (except that some small percentage of it probably winds up in dumps, where it leaches into the ground, adding to the general garbage heap we're making of our planet). There's been
a law in effect for a little over 7 years that restricts the use of hazardous substances like lead. If you have old LG charging cables from 2006 or earlier, there may be some lead solder in them, but it's not really a significant threat these days unless you start chewing on them.