Hi everybody - I'm new to this site and just starting up a set for the first time in 20 years. I bought a an oval track with DCC controller and then bought the Ez Track Expander set with two switches. I got everything hooked up (except for one 9" straight track i FORGOT TO GET) but on each switch there is a red wire coming out of it with 2 red u-clips which i assume goes to a power supply, which of course the store forgot to sell me or tell me about. Is there a special one I need or can I use a general one with a specific voltage Any help anyone can provide would be great, as I'm still waiting to hear back from the store. Thanks.