A door lock is a fickle thing. It can function perfectly in the morning, but won’t let you inside a few hours later. Of course, many keying problems can be solved without professional help, such as when your keys won’t turn and get stuck inside the lock. But there are instances when you must summon a locksmith right away or risk sleeping outside for the night.
Your Key Broke Off in the Lock
So your key was stuck and you have tried spraying it with WD-40 or a silicone solution. But, when you tried to wiggle it, it snapped and broke off while inside the lock. If there are still a few millimeters of metal jutting out from the lock, perhaps you can still use a flathead screwdriver or pliers to remove it yourself.
But when nothing sticks out—or worse, you can no longer see the metallic part of the key—the chances of you recovering the broken piece yourself are extremely slim. Read more from this article: http://bit.ly/2sGnQXT