Most commercial guitar wiring that I've seen in my own guitars looks like 24- gauge stranded copper wire. Speaker wire might also work. You might wanna go to Radio Shack and see if they still sell a wire gauge sizing template; HD and Lowe's may also have such in the Electrical section. Then you could check the gauge of your network or phone cable. Thinner wire has a higher gauge number, thicker wire usually has a smaller number, often labeled "AWG."
Take your question over to the "CBG Wiring and Electronics" group here on CBN, and there will be wiring experts to help you.