Unless you are hiding something, why wouldn't you grant them Access?
You should get a local lawyer to further explore your rights and potential liabilities.
NOTE: (1) I may be guessing and/or not even licensed in your state; (2) We have not established an attorney-client relationship; (3) Sometimes you get what you pay for; and (4) If you want to send me a gift, my favorite color is orange.
I agree with the previous answer. Unless a statute , lease provision, easement, search warrant, or court order that demands access you do not have to allow it. Just ask them to "cite their authority" that forces the party seeking access to show you how they have the right.
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