I'd assume so. I doubt you are going to need much EL Wire for a ring. The EL Wire is what is used to make tron-like costumes etc.
A faraday cage is simply a coil of wire with a magnet in it similar to the shake lights. I'm not sure if there is enough room for something like that. If you can build a cage into a ring you simply need to shake the ring to power it, which will be cheaper in the long run than buying watch batteries.
Even if the EL Wire is somewhat expensive, it may still be reasonable when you consider the price of the spectrum set DC Direct put out.