1978, August 20: Biddeford Woman’s Fiery Death
On August 20, 1978, a 54-year-old woman was found burned to death in her apartment in Biddeford, Maine, USA. "No cause known."
This is the first listing of this incident in Anomalies, and therefore will require more research to confirm it. This is especially true because the above comes from Jenny Randles and Peter Hough's 1992 book, Spontaneous Human Combustion; this book gives almost no sources for the accounts it relates, most often attributing them to "Author's own investigation" and "Historical archives traced and researched"... which essentially means "Just trust us." In this case, the above is attributed to Fortean Times magazine, but we are given no date or issue number. For this reason, this account is marked as both "Unreliable" and "Investigate;" I will add new information as I get a chance to dig further.
With the few details above, there is no reason whatsoever to consider this case supernatural. I'll see what I can dig up though; you never know until you do. In the meantime, I'm marking this account as a "Mystery" rather than an "Anomaly."