I hear this has been attempted before, by a young girl. Her father was searching for her one day, and went to check in her room. He found the note on the floor, cut into little pieces, and assembled what he could, making out what seemed to be a suicide note, but missing that key shape in the center. He looked around for more evidence of some sort when he noticed a paper key sticking out of this 'invisible lock'. Cautiously, he approached the door to the room, and closed it. He eyed the key over-it was indeed what had been missing from the note. But how could it sit there like that, simply floating in place relative to the door? Curious, the man reached out, and turned the key. The door in front of him opened slowly, revealing an entirely new world.
A short distance away from him, a small swarm of activity circled around a crumpled body, lashing out and tearing at the flesh. Among the horrible screeching and ripping of flesh, the man could hear a faint, but distinct whimper. Terrified, the man inched forward, going against his better judgment. Again, a voice called out to him. He knew it instantly. He fixed his gaze back to the crumpled body amidst the...'demons', for lack of better term, only to find his little girl reaching out to him before she was again beset by her terrible fate.
His fear overcame his rage, and he backed out of the door just as quietly as he entered. He found himself back in his little girl's room, sobbing uncontrollably. He shut the door, pulled the paper key out, and tossed it to the ground. He was later found dead with a note containing this information nearby. He had apparently hung himself out of fear and guilt.