Prepare to develop a product that can be electrified on the door or lock, and the voltage will not electrocute or corona people. Is it allowed by law? Can I apply for a patent?

First of all, from the perspective of intellectual property, as long as your product is novel and original, you can apply for a patent.

Secondly, from the perspective of protecting public safety, your products obviously endanger public safety, and the relevant departments will definitely not allow you to produce and sell them.

There are many such cases. For example, in order to prevent melon thieves, melon farmers set up a low-voltage power grid in their own Gua Tian and set up a sign of "Electric Danger". But even so, even if the person who was electrocuted was a thief, melon farmers still constituted a crime of endangering public safety.