I had a missing bulb in a string of xmas lights, so I decided to just cut and splice. There are 4 "wires". 2 of them were normal copper strand but the other 2 were like hair. What do I make of that? They can't be conductors, can they?
Yes they can be conductors. Take a look at the light bulb leads, they are about as thin as hair. When I want to bypass a light on string of xmas lights, I just jam tin foil in the light socket hole.