Elinor Juste a Ghost of the Living. The McRae Series

San Francisco, 1906. Broderick McRae is again being haunted. As the city struggles to recover from earthquake and fires, an unseen spirit begs McRae for help. This is no revenant but the essence of a living woman, Elinor, who lies in a coma thousands of miles away. Her husband tried to kill her, and he may yet succeed if McRae doesn't intervene. His main problem is that no one believes him, not even his wife.
In fact, she suspects he is having an affair. And he has no idea how to find Elinor's husband, let alone how to keep him from killing her. Second story of the McRae trilogy.