Excuse me, why is there a snapping sound when undressing at night?

In dry and windy autumn, people often encounter this phenomenon in their daily life: when they take off their clothes and sleep at night, they often hear crackling sounds in the dark, accompanied by blue light. When they meet and shake hands, as soon as their fingers touch each other, they will suddenly feel the sting of their fingertips, which is shocking; When you get up in the morning to comb your hair, it tends to "float". The more you manage, the more chaotic it is. When you pull the door handle and turn on the tap, you will get an electric shock, and you will often make a "bang, bang" sound. This is static electricity generated in the human body.