My mother had a phone listing for ten years after she died. (Complicated reason but it happens.)
I have my Grandfathers phone nuumber and he died in 1954. People still think he needs his house resided.
FWIW...
Wiki article:
Illness and death
In late 1994, Dunham was living and working in Indonesia. One night, during dinner at a friend’s house in Jakarta, she experienced stomach pain. A visit to a local physician misdiagnosed her symptoms as indigestion.[1] Dunham returned to the United States in early 1995 and was examined at the Memorial Sloan-Kettering Cancer Center in New York City and diagnosed with uterine cancer. By this time, the cancer had spread to her ovaries.[14] She moved back to Hawaii to live near her widowed mother and died on November 7, 1995, at the age of 52.[29][39][40] Following a memorial service at the University of Hawaii, Obama and his sister spread their mother’s ashes in the Pacific Ocean at Lanai Lookout on the south side of Oahu.[29] Obama scattered the ashes of his grandmother (Madelyn Dunham) in the same spot on December 23, 2008, weeks after his election to the presidency.[41]