How to make a slip ring connection for a spinning sign

I’m working on a new project and I need an electrical connection that can rotate 360 degrees. I could purchase a slip ring, rotating electrical connector, or better yet a rotary transformer. Then again, I could just try to make one from a DC motor. Do you have any suggestions for making, or *gasp* buying, a slip ring connectors? If so leave them in the comments. Thanks!

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