Make a no battery home radio, tune it to an AM band then listen to it with no power source to see how strong AM radio waves are with no amplification. (You should still be able to hear it just fine)

Exactly. That is why idea of using ferromagnetic particle as simpliest possible long-wave receiver to work inside human body could be valid. Such receiver in correct place could create "voices in head". Some occasional proofs that it works was documented in history, f.e. when one subject got teeth stop containing metal powder as filler, he began to hear broadcasts from nearby AM station, received and demodulated by his teeth and then sneaked into nervous system. This created effect of "voices in head".

Also remember AM Radio bands are on the weaker end of the radio spectrum and by law those radio towers have to be at the "Lowest wattage possible to complete the transmission".

Not at all. long/mid-wave AM transmitters have to be very powerful to reach good coverage. Exactly because AM is at the weaker end of spectrum. To deliver noticeable energy to remote receiver you need a lot of power at transmitter. Check wattage of real AM stations of the past.