Depends on the local zoning ordinance, if any, which may regulate the siting of mobile homes, or ban them altogether. Typically zoning ordinances, if enacted, affect smaller areas of a state like a township, county or city. You should consult with a land use attorney, builder, or architect in the area where you are thinking of siting the mobile home. You can call the local building inspector as well. The local zoning ordinances are always available at town halls, and often at area public libraries or often now on the website of the municipality. Mobile homes may be regulated within the zoning ordinance, allowable in some use districts but not others, or in a separate ordinance (which would tend to ban them entirely from a township).
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Mobile homes are used for all sorts of purposes. Think about the used car lot, the construction office, even a temporary school. Mobile homes are not always used for residences and some are even designed for other purposes. Just make sure the placement of the unit is legally allowed by the owner as well as local ordinance.
Generally there should not be any issue with what you are proposing if it is used only as a temporary placement and not for residential use. If you intend to park a mobile home in a location permanently, then it will not matter if you are not using it for a permanent resident - you will still need to comply with local zoning laws. There may be some state level requirements in Illinois, but where you want to look for a definitive answer will be with the local jurisdiction - e.g. county or city. Contact the planning or development department and they can tell you what is allowed with regard to mobile homes and the subject property.