If it isn't packaged for reptiles, it probably hasnt been properly cleaned. Sphagnum moss is popular for landscaping and gardening projects. For these types of uses, the presence of mites and parasites is inconsequential, and so it isn't cleaned for them. If it is packaged for reptile use, it has been properly cleaned and treated to prevent the spread of mites and parasites.
A safer bet is bleach-free and dye-free papertowels soaked in water, wrung out gently, and palced in a "humid hide". For examples of humid hides, do a search and you will get a load of information.