How does Thor manipulate Lightning?

Let's assume that Thor can control the weather, through magic. This would mean that he could control both wind and atmospheric charges. Thus, he could create the necessary atmospheric conditions for  a lightning storm

How does Thor shock people?​
Mjolnir is an electrical conductor. By creating a condition ripe for electrical activity, it increases the chance of lightning happening. Electricity tends to follow the path of least resistance from a high potential to a low potential, so if Thor can create a high potential in the atmosphere and then direct a path of low potential through an enemy, he could direct lightning through them. 

How does Thor not get shocked?
Electricity follows the path of least resistance. Therefore, to prevent his own lightning from going through him, Thor must create a sufficiently high resistance in his own body. Alternatively, Thor's Asgardian blood may act like a Faraday cage, in which electricity arcs around the surface, rather than going through the middle of it.