What causes static electricity

A stationary electric charge, typically produced by friction, that causes sparks or crackling or the attraction of dust or hair

There are several ways this condition can be caused:

One way is by rubbing certain materials together or pulling them apart. Another way that static electricity commonly seen is when a charged material is brought near a neutral material. This is called electrostatic induction. You can also cause static electric separation of charges by using pressure in certain materials or using heat in other materials.