Fact sheets, brochures, field operations manuals, etc., are reflections of policy, not the actual Code of Federal Regulations. It's not at all unusual for fact sheets and FOMs used by agencies to deviate from the CFR. They often attempt to assert authority they do not actually possess. My agency's FOM often departed from the CFR, usually stopping short of contradicting the actual regulations. There's a lot of bluffing in federal regulatory enforcement. Don't help them by tipping your hand just because they bluff or call.
If the FCC actually has the authority to inspect "radio equipment" under any and all conditions, on private property, there's nothing to stop any regulatory agency from inspecting your home, without probable cause, warrant, etc., to be sure your non-existent sweatshop is operating within OSHA and Dept of Labor regs; that your non-existent recycling center is complying with EPA regs; etc.
Don't get me wrong -- I support reasonable federal regulations designed to protect people from actual harm, and to preserve the common resources in the environment. There's plenty of history to show how unregulated private industry and individuals have abused employees, wrecked waterways and slaughtered wildlife nearly to extinction.
But federal regulatory agencies enforcing civil regulations specified in the CFR do not possess special privileges to flout the Bill of Rights. And any attempts by the FCC to assert the authority to inspect an alleged radio station in a domicile or building where there are no licensed amateur radio operators should be peaceably opposed on ethical grounds. Let the courts sort out the facts.
This ain't the UK where, for decades, OFCOM used detection equipment and triangulation to locate homes with televisions and radio receivers to be sure they're paying taxes for the privilege of being an audience member.
If the FCC shows up asserting the right to inspect your home, place of business, vehicle, etc., for "radio equipment," and you are not a licensed amateur radio operator, ask to see the warrant. If they don't have one, politely thank them for their time, perhaps apologize that they made a trip for nothing, and bid them farewell. If they show up with federal marshals, warrant in hand or not (it's very unlikely marshals will accompany inspectors without a warrant), it's up to you whether to continue to assert your rights to privacy in your private property.
Beyond that, the usual next step is to appeal to the federal regional office and/or magistrate of the federal district court. I've attended some appeals (again, not FCC cases) at which the person cited chose to represent themselves, and sympathetic magistrates actually coached the appellant through the process. OTOH, there are other magistrates who lean the other way, toward heavyhanded enforcement, so it's a gamble to appear without legal counsel.
I think folks will find this entire page to be relevant, from the horse's (insert appropriate body part) itself:
https://www.fcc.gov/reports-research/guides/inspection-fact-sheet
Here are some very relevant sections:
Both licensees and non-licensees must allow an FCC Agent to inspect their radio equipment. Along with the privilege of possessing a license come responsibilities such as knowing the applicable rules, including allowing the station to be inspected. Licensees should be aware of the Commission's right to inspect. Equally important, FCC Agents are allowed to inspect the radio equipment of non-licensees. Non-licensees include those individuals or entities operating in accordance with Part 15 of the Rules. Non-licensees also include those who should have a license to operate their equipment but have not obtained a license and are operating without authority.
Q: Well then, if I am a low-power broadcaster and don't have an FCC license, they need a search warrant, right?
A: Wrong again. The FCC agents have the authority to inspect all radio equipment; even if you do not have a license, the FCC can still inspect your equipment. Section 303(n) of the Act gives the FCC the right to inspect all "stations required to be licensed." This language covers your low-power radio station. The FCC agents are inspecting the equipment, not searching your house.
HERE'S THE DEAL-----
They may have the "legal authority" to enter your residence and inspect your equipment under all those different scenarios----
HOWEVER---- unless they are backed with GUNS and FORCE, you can prevent them from entering your residence, with your verbal refusal!
(The legal issues are a matter to be adjudicated by courts, at a later date!)
I speak as someone who has been 'allegedly' busted by the FCC--
I denied the supposed 'crime', and would not allow any inspection of my alleged 'equipment'-
and the FCC agent was alone... so he delivered his 'verbal warning', and went away.
The word 'authority' has no meaning unless it is backed up by lethal force....
(Now, in the case of US licensed ham operators, YES, they can later take away your license for your refusal to permit 'inspection' of your station--
but with that understanding, you STILL don't have to let them 'inspect' you,
unless they employ lethal force which you cannot resist...)
(FCC Agents are only "bureaucrats"--- they are NOT 'law enforcement officers'-- they can't arrest you for supposed crimes, and are most likely not armed-- they only attempt to persuade you to incriminate yourself!!)
Of course, if they were to arrive accompanied by Federal Marshals or local law enforcement, that is another matter entirely--
but is almost entirely NEVER the case...