Is there a test for mold that can be used in homes?

In most cases, laboratory testing/sampling is not necessary for mold detection. Also, accurate mold testing is expensive. Do-it-yourself kits you may purchase will not provide accurate useful information. If you can see or smell mold, then you have it! Rather, utilize the money to remove the mold and prevent it from reoccurring by fixing the moisture problem that permitted the mold to grow.
Laboratory testing can identify the type of mold, but regardless of the type, it is not healthy to live in a moldy environment. In addition, the method of removal is the same for all types of mold, so generally it is not necessary to know the type.
Since no EPA or other Federal threshold limits have been set for mold or mold spores, sampling cannot be used to check a building’s compliance with Federal mold standards.
If sampling for mold is done, it should be conducted by professionals with specific experience in designing mold sampling protocols, sampling methods, and interpretation of results. Sample analysis should follow analytical methods recommended by the American Industrial Hygiene Association (AIHA), the American Conference of Governmental Industrial Hygienists (ACGIH), or other professional guidelines. Types of samples include air samples, surface samples, bulk samples (chunks of carpet, insulation, wall board, etc.), and water samples from condensate drain pans or cooling towers.
A number of pitfalls may be encountered when inexperienced personnel conduct sampling. They may take an inadequate number of samples, there may be inconsistency in sampling protocols, the samples may become contaminated, outdoor control samples may be omitted, and you may incur costs for unneeded or inappropriate samples. Budget constraints will often be a consideration when sampling; professional advice may be necessary to determine if it is possible to take sufficient samples to characterize a problem on a given budget. If it is not possible to sample properly, with a sufficient number of samples to answer the question(s) posed, it would be preferable not to sample. Inadequate sample plans may generate misleading, confusing, and useless results.
Keep in mind that air sampling for mold provides information only for the moment in time in which the sampling occurred, much like a snapshot. Air sampling will reveal, when properly done, what was in the air at the moment when the sample was taken. For someone without experience, sampling results will be difficult to interpret. Experience in interpretation of results is essential.
For more information on mold and mold removal refer to the EPA web site.