Ashes (Walker), book 1: Ashes to AshesMelissa Walker2014

CALLIE McPHEE KNOWS ALL THE CLASSIC CHARLESTON GHOST STORIES BY HEART.
WHAT SHE DOESN'T REALIZE IS THAT SHE'S ABOUT TO BECOME ONE.

When Callie's life is cut short by a tragic accident, she expects to find nothingness, or maybe some version of heaven. Instead, her spirit travels to the Prism, an ethereal plane populated by the ghosts she thought were fictional. Here she meets a striking and mysterious ghost named Thatcher, who is meant to guide her as she learns to haunt and bring peace to the love ones she left behind.
With Thatcher at her side, Callie watches in agony while her father, her best friend, and her boyfriend mourn her - and she's not sure she wants to help them let her go; she may be invisible, but she's still here. However, as Callie desperately tries to make contact with the people she left behind, she uncovers a dark secret about the spirit world: The angry souls that always populate ghost stories are real, dangerous, and willing to do anything to stay on Earth, threatening the existence of everyone's he ever cared about.
When she fights to save them, Callie will learn that while it may no longer beat, her heart can still love - and break.