The 21-year-old former finalist sang her own song 'Beer Fear', which she had also performed during her first audition on the ITV1 show, at the festive event in Meadowhall Shopping Centre.
Speaking to the crowd, Spraggan said: "Thank you for the support I've been getting over the last few weeks, you've been absolutely amazing.
"That was the most amazing thing that has happened to me."
She later added on twitter: "#capitalfmswitchon crowd you were AMAZING. Getting on that stage made me feel the best I have in weeks. Thank you."
The Wanted and last year's X Factor finalist Misha B also performed at the concert.