Custodian tests vary between school districts, but some types of question are fairly standard, such as the correct procedures for preparing to handle biological spills or safety precautions for handling electrical equipment. It is always best to seek out a specific study guide for the relevant school or local district.
Custodial exams are sometimes described as tests of common sense. A basic level of literacy is required, and a section on following written instructions accurately is common, as this is often an important part of the role. Knowledge of proper cleaning techniques and equipment is also likely to be tested, though an allowance may be made for some of this knowledge to be developed by training after appointment to the post.
One of the most important parts of the test is the section on safety. This generally tests the candidates' knowledge of topics such as safe lifting and handling of equipment, use of potentially hazardous chemicals such as cleaning fluids, and an awareness of electrical and other potentially life-threatening hazards in the workplace.
Some states' tests cover more than one role. For example, the New York State test schedule has a Custodian/Bus Driver exam that can be taken by candidates seeking a dual role.