Outlet stopped working, found it is only two wire
Note that if you can't put in a grounded outlet, a gfci outlet is an acceptable alternative for safety. I've done that at several places in my old house. When installing without a ground, there's a sticker that should be applied essentially saying "yes, we know there's no ground, don't panic if the tester tells you so but also don't expect to use anything plugged in here as a ground."