Seeing people in jail foretells small worries for the dreamer, such as disappointment in associates, or losses due to negligence on the part of others concerned.
A jailer in the dream is another form of a wish to elude responsibilities that have become unbearable.
If the jailer is with other people then the dreamer would like to eradicate them. Just to see a jail may be a guilt complex for some very minor infringement of the law such as a traffic violation.
Dreams of a jail or prison guard signifies that you are coming to grips with the part of you that holds you captive behind bars of guilt and shame. You are realizing he key to set you free is in your own hands, and it lies in your ability to make amends, and forgive yourself and those who have harmed you. See Prison.