This happened about three years ago to my boyfriend at the time, but it occurred at my house. He was taking a shower one afternoon, and as he was he said he saw someone walking around outside the window.
There is a window in our shower, but instead of just glass, it is glass bricks. Which if you have ever looked through, you know you can see sort of through them, but not clearly, it's very blurry. Anyway, he saw someone walking around back and forth through the window, and he said as they appeared, the water in the shower went cold for a second, like it does when someone turns on the faucet.
When he got out of the shower, he asked my mom if she had been outside, she said no. He then came into my room, where I was, and says to me, "That was pretty funny what you did, with the water and all." (There's a sink with a faucet located outside where the shower window faces.) I told him I had no idea what he was talking about. He didn't believe me. It took him a couple days before it settled with him that I was telling the truth, and that something weird had happened.
A week or two later, a friend of ours came over. While he was here, he decided to take a shower. While he was in there, he reported the exact same thing. There was a person walking around out there, and when they walked by the water went cold. He didn't even know about this happening to my boyfriend.
Now you might just think, well maybe there WAS someone walking around out there! However, they both described this thing as being completely black, like someone wearing a hood. You couldn't see any features.
Our friend that took the shower, said that whatever it was, walked by a few times, then stopped, and got up very close and stared into the window at him for a long time. He thought it was just my boyfriend messing with him. When we told him what had happened a week prior, he started getting really creeped out.
I asked him if he could see any features, he couldn't. He stood in the shower, and I went outside to the other side of the window, and he realized you can make out the face of the person on the other side of the glass, he thought it was normal to not be able to see actual features, he thought it was normal for them to look completely blacked out like it was. He said whatever it was, got very close to the window; they leaned over the large counter and peered at him through the window. In order to do this you pretty much have to be really tall, and place your hands on the counter outside the window, which is very dirty. There were no hand prints there.
After this I pinned a towel over the window, I for one do not want to see what they saw! Ha-ha.
After stories like these, you can see why everyone is afraid of my house. Even people that I never mention anything to tell me they just don't want to be alone anywhere here. It gives the bravest of my friends the creeps just to have to smoke a cigarette outside; they will smoke half then run back in. They don't even know the stories!