I am part of the official NaNoWriMo facebook group and somebody posted about unsolved mysteries. People have been commenting on various mysteries thru the ages. I commented about the “Beast of Bladensboro” in North Carolina.
The story goes between 1954 and 1955 there weird animal killings, domestic and wild animals. The victims spanned from pet dogs to deer. Then the killings stopped. Speculation abounded on who or what had done the killings. One theory said it was a cougar or a large cat that had possibly escaped captivity. There were lots of more interesting theories suggested.
When I lived in the mountains, people talked about the Brown Mountain lights. The theory goes the lights are lost souls forever wondering the mountain in search of peace. Another is aliens running around just to mess with up. Another theory is the flashes are reflection of vehicles on the road which is why the lights are always moving.
So what interesting stories or mysteries do you have lurking in your backyard. Sometimes those homegrown legends can inspire your writing and spark your imagination.