You'll want something that encloses the snake completely. Such as:

http://www.reptilebasics.com/Hide-Boxes-p-1-c-282.html

Alot of people use dark colored plastic bowls and cut out an entrance for the snake. Some people use clay pots, there are a lot of alternatives but the main point is to keep out light and have a hide the animal feels snug and secure in on all sides.