X-ray sheet can open locked doors. This is true in France. So, X-ray sheets are not only used by physicians to check the state of your internal organs but also by door specialists to unlock closed doors. Does this surprise you? It surprised me. But then, I have my friend vouching as a witness to this operation and also performing it. Don't worry, my friend is a law-abiding expatriate and he was trying to get inside his apartment after conveniently forgetting the keys inside. This happened twice.
When my friend was locked out his apartment the first time, he called up a door specialist. The door specialist arrived carrying a suitcase, which is popular with all workers who specializes in the sundry tasks associated with a house. After the examining the door, the specialist searched his suitcase and pulled out a X-ray sheet. He then placed the X-ray sheet in the narrow space where the door meets the wood attached to the wall. The X-ray sheet was placed in the lower half of the door. Then, in one swift move, he pulled up the X-ray sheet passing over the lock in a matter of microseconds. The door was open.
My friend was relieved to get inside the apartment. But his happiness was short lived as he was presented with a bill of 90 Euros. The cost made him wiser. Now, he began to double-check and triple-check if the keys were with him before he stepped outside his apartment. But this was also short-lived. In a matter of days, he was again locked out. This time, he didn't call the door specialist. Instead, he called up a colleague, visited the colleague's house and brought back a X-ray sheet. The X-ray sheet worked and he was back inside the house.
Now, does my friend carry a X-ray sheet with him all the time? Does he double-check, triple-check and quadruple-check for the keys before leaving home? I do not know. Reading this, are you going to carry a X-ray sheet too? If you are thinking of carrying one with you, let me remind you why this worked. This worked because my friend has a habit of pulling the door with force to close it on his way out. He doesn't lock it. If you also have the same character traits, then this might work for you. As of writing this, I am not sure if this solution is location specific; in other words, works only in Paris and other parts of France.
As a foot note, please try this operation only on your door. Trying this on your neighbor's door or in that matter any other person's door will have undesirable consequences.