In middle school we read a book called The Giver, which is about a society where everyone is the same. People's partners are picked for the, their jobs are picked for them when they reach a certain age, and their kids are given to them. In middle school it was difficult to fully understand all the nuances and implications of this text, but not I can see that it can be labeled as a postmodern work.
The Giver brings to question the trustworthiness of government and those in charge. Going more specific, it can be said that the book questions the merits of communism. Its main postmodern technique used is absurdism. Many parts of this story are absurd. First of all, most people in this society only see in black, white, and shades of grey. Memories and information of the past are contained in a person; it is that person's job to keep that information, and access to that information allows them to see color (somehow). The rigid structure of the society is also absurd. People are watched and judged from the moment they are children, and this is what determines their jobs in the future (which they receive when they're still kids). The age someone is given a bike is recorded, and taking an extra apple to eat is also recorded. The absurdity of all the regulations satirizes over powerful leaders/governments, showing them in a tyrannical light.
Paranoia is also used in The Giver. Once the main character (and we, the audience) start learning more about the society and how it really functions, darker sides of it begin to emerge. People who get problematic are killed. A baby born when they shouldn't be is killed. Up to and when the main character escapes this community, paranoia builds on if they will be discovered and reach the same fate. The unsettling feeling that comes with this paranoia serves the postmodern aspect of the novel because it puts over powered governments in an evil light, calling to question methods used to stay in power.