Beings (1998)

Since as far back as Kyle and Evie Preston can remember, their grandmother told fantastical tales about elves who had been trapped underground by giants for thousands of years. Now grandmother is gone, and the siblings are surprised to discover that they have inherited a decrepit gold mine and a family home they never even knew existed. Upon discovering that grandmother's far fetched stories have a bizarre basis in reality and that by freeing the fairies from the mine they will discover a cure for their terminally ill father (Bernsen), Kyle and Evie race against time to free the trapped fairies and save their father's life.