Death of a Fox — Jan Roffman

Holly Villas - a strange old mansion, a house divided by ghosts of the past and the secrets of the present...

Joanna Crane wasn't unduly nervous living in such complete isolation, until she discovered there was no explanation for the sound of footsteps - where footsteps had no right to be; cigarette ashes - newly dropped in a house where no one smoked; double orders of dinner - by a man who ate barely enough to keep him alive...

She realized there was someone else living in the divided house, but it was quite by accident that she discovered who he was...Then, as she poised herself to run for her life, a door slowly opened, and Joanna knew she had waited too long...

Also published as The Reflection of Evil