Lead Capture Form "ghost"

Hi, I got a problem with my lead capture, I was adding a "checkbox" field but I misclicked, so now I got a "ghost" flat field displaying on browser but not in lead capture setup panel.
I tried to delete all fields, create more, and delete again, but still got this problem.

I'm sorry I can't link my website because it's not ready yet to be on.

Thank you, Simone

///// Solved /////
I went into SQL table lead_data, then I've been able to delete the wrong entry.
Sorry for being a bit newbie, I hope this could help someone