Are there not persons who evoke these evil spirits?

Is it possible for beings to live on this earth in their Astral bodies? 

Thousands of spirits live on what you call your earth, but it does not seem the same earth to them.

Can they do evil? 

They can do great evil but it is overcome and generally becomes negation; as long as you keep your consciousness alive, they can do you no harm. It is only by following them from curious motives that you come within their evil sphere.

Are there not persons who evoke these spirits? 

The powers they evoke are not the highest and they are obliged to turn from the path that has been appointed and, by so doing, miss their opportunity to progress, and in the end will find themselves obliged to return with bleeding feet.

—Insight