I work in senior housing and have a schizophrenic resident that will swear someone was in her house. If your mom has any kind of mental issues she forgot that she turned the water on. If not then maybe a ghost.
So I slept out at a friends house last night, and when I returned home the first thing I heard was my bathtub running. I assumed my mother was in the bathroom doing this. I headed down stairs to soon find out my mother was in her bed. I quickly ran back upstairs to find the bathtub running. Both the hot and cold water were turned all the way. There were a few things moved around in the tub like shampoo and face wash. However, the door to my house was locked. My mom swears she didn't do it. My initial reaction was to think it was an intruder, and i am still open to that possibility. But why would someone not steal anything. My mom thinks it was a ghost. I am much less open to that idea, but I honestly have no idea what it could be so I am game to here all explanations.