Zeke Simpson is the "grandfather" of Abe-Boy Simpson.
There is a blackout at Christmastime so without any TV, Abe starts to recall a boyhood Christmas at his family's sawmill confusing his own life with various TV shows.
On The Waltons, also about a large family running a sawmill during the Great Depression, the grandfather was named Zeb Walton and in Grampa's story his own grandfather is named Zeke Simpson.
Zeke is a shortened nickname for Ezekiel and Ezekiel Simpson was a name on one of the tombstones in the opening of Season Two's "Treehouse of Horror".