In Franklin's House, by Beverly Lauderdale
In an isolated, turn-of-the-last century house on a Northern California hillside, Kate steps into a deserted room that exudes a strange appeal. Based largely on her reaction, she decides to buy the Victorian and to move from Iowa with husband Dan, whose affair has rocked their marriage.
Lost and far from her home and familiar things, Kate is drawn repeatedly to the room where she finds a diary written in 1906, and a delicate rose bud necklace. The diarist describes visits from her deceased husband, Franklin, a poet. Captivated, Kate can't resist donning the necklace, which, to her amazement provides a portal though which Franklin can enter Kate's world.