Every Breath by Eve Vaughn

Damon and Brandi Evans shared a bond so powerful that when Damon is murdered, he spends his time in the afterlife, watching over her. But when Brandi gets involved with the man who killed him, Damon can no longer stand idly by. In a desperate act to save the woman he loves; Damon makes a deal to go back to Earth to wrest his woman and their children out of the hands of a madman.
But there’s a catch…he returns in the body of Mason Collins, a man with a dark past.
Two years after the death of her husband, Brandi Evans attempts to move on with her life and begins dating, however she can’t stop loving and comparing everyone to Damon. That is, until she’s hit by an unexplainable attraction to Mason. As she gives in to the forbidden passion of his touch, someone will stop at nothing to ensure that their love is destroyed. Forever.

Note: Book was previously titled Every Breath You Take