Try radio shack, Home Depot or any place that electrical contractors shop. It is possible that if you heat electrical tape with a heat gun you will get what you want. BTW, 12v home lighting systems are often uninsulated so insulation might not even be needed in your case.
2000 Montague CX, I do not recommend it, but still ride it.
Strida 3, I recommend it for rides < 10mi wo steep hills.
2006 Rowbike 720 Sport, I recommend it as an exercise bike.
1996 Birdy, Recommend.
Wieleder CARiBIKE (folding), decent frame.