Re: tying flies
On the subject of copper wire, tons of thin copper strand can be found in transformers used on all sorts of electric equipment like radios, TVs, games, computers etc. It is generally very thin. (as Cliff said, unplug them first)
I gave up on using solder years ago except for very large, heavily weighted streamers (size 2 for instance). One reason is that most solder contains a chemical flux that is really nasty stuff.
I made flies for pan fish and bass out of dog fur for lots of years and caught plenty of fish on it. It was a free renewable source for "practice" flies and I suspect fine horse hair may work also. Of course if you have any bunnies.....
If you keep your eyes out, you will find all sorts of real and synthetic furs (stuffed toys for instance), feathers and other tying material just laying about. Maybe a family member is into embroidery, knitting, crocheting or any other type of craft project. Lots of these materials are good.
I don't suggest road kill. The disease possibilities are too great.