After my grandfather passed away, my older brother took over his farm. During the summers, I would move in with him, and help him with the farm work. (I was probably 14 or 15 years old when this particular thing happened) The front door on that house had one of those push-button locks on the doorknob. All you had to do from the inside was turn the doorknob, and the door would unlock, and you would hear a combination pop/click sound as the lock released. I was very often the first person that would leave the house in the mornings, so I was very familiar with the sound of the lock releasing as I would leave the house. One time, my brother must have left the house, and locked the door on the way out, while I was in the barn. The key was in the house, the door was locked, so I couldn't get into the house. Having no spare key, I decided to pry open the wood chute door, and climb into the basement. It took a bit of time, but I was able to get into the house. The basement was dark, so I was already a bit freaked out, but I made my way through the basement, and up the steps, into the house. What really freaked me out however is when I reached to turn the doorknob to unlock the door. The doorknob turned right open, with no familiar click/pop. My 14/15 year old brain immediately surmised that the house was haunted, and that a ghost had unlocked the door while I was in the basement. I sprinted out of the house, and did not go back in until my brother got back. Admittedly, my experience is not as terrifying as some, but it scared me pretty good at the time. Still not sure what happened with the lock, best I can guess is that my trying to open the door from the outside must have shifted the workings of the lock around from their normal position, so that the lock didn't make it's "usual" sound when it released. Or maybe Grandpa unlocked it for me :-)