National Trust houses are bursting with ghost stories. The spirits of former owners, staff, even pets haunt their former homes and walk hand-in-hand with those living there today. Simply walking into an historic house can be enough to make you shudder, such is the intensity of the sense of the past. The figure of Elizabeth, Duchess of Lauderdale wanders solemnly through Ham House in Surrey, sometimes haunting the Chapel, sometimes accompanied by the...