The Secrets of Wilderfort Castle (The Wilderfort series, #1)

Agatha Wilderfort has spent years trying to build a life in the city outside of the sleepy town where her aunt raised her, but is pulled back home when her aunt's sudden death leaves their family manor in Agatha's hands.
She arrives to find the castle in grave need of repair and a local nobleman, Lord Caspian, sniffing around, clearly eager to get his hands on her inheritance. She hires several workmen and an assistant who knew her aunt and they start on the renovations.

But Agatha's aunt was...