What is this tingling in my spine?

I have this tingling on my spine that's driving me crazy. The best way Could describe it is it feels like a piece of tape is on my skin right over my spine. Its not painfull, just weird felling. I'm 23. I'm probably twenty to thirty pounds over weight but I have always been and its never bother my back so I dont know if that has somthing to do with it or not. The tingling is on my spine right in the center (not lower or upper back). Please HELP!