Not with earth as a medium, but "the old scientist" used the air with some results:
I must assume those boxes are like the ones I've tried. i.e. they are non-ferrous.
When you see such a demonstration keep in-mind that a non-ferrous 'faraday cage -cake box-' will only block the electric side of the transverse wave. As long as you are in the near-field of the transmitter you will receive a signal because the magnetic side still penetrates the box. At that frequency he may be able to receive a signal even further away.
He should try a steel box that is grounded, like a true Faraday Cage. There should be no signal received.
It is possible to use my suggestion and still receive a signal but that would be due to the magnetic portion of the transverse wave inducing a current in the cage. The magnetic field from that induced current is mirrored inside the box at a much lower level.
"As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality." - Einstein
"What we observe is not nature itself, but nature exposed to our method of questioning." - Werner Heisenberg