Voice From the Grave by Clarissa Ross

FROM AN EVIL PAST...It was in an East Side restaurant that Ann Martin caught her first, unnerving glimpse of her husband's ex-wife. A woman who had been killed in a plane crash one year before. Yet Rolf had seen her too. And then, at their chic but ominour townhouse - haunted by memories of Rolf's first stormy marriage - the terrifying phone calls began: in a ghost's voice, insistent, ugly demands for payment for silence about a crime about which only the first Mrs. Martin could have known. Was Ann losing her mind? Could she protect her husband against threats from a being who could not possibly exist? Then a hand from beyond reached out for Ann herself and she knew she must face the impossible...or die. Paperback, 1971 Goodreads: 2.50