Energy leakage from a waveguide

Jun 2019
Are the electric and magnetic fields within a waveguide operating at microwave frequencies visible outside of the waveguide? If I connect a probe across different points along the exterior of a waveguide, will I see a signal? If I loop an insulated wire around the outside of a waveguide, will I see a signal at the ends of the wire?

If the answer to any of these questions is yes, then why doesn't that signal radiate away from the waveguide and hence attenuate the signal within the waveguide? Wouldn't that pose health hazards to someone working around a high-power waveguide?

If the answers to these questions is no, then why can't I see the signal outside of the waveguide? Isn't the electric potential outside the waveguide wall virtually identical to the potential on the immediate interior of the wall? Why wouldn't the wire loop sense a transversely varying magnetic field inside the waveguide?

I appreciate any insights from anyone who is familiar with this topic.
Jun 2016
First a disclaimer: I know very little on this topic...

However, my impression is that the whole purpose of a waveguide
is to contain the microwaves within the waveguide structure
(as is indicated by its name).
I imagine it to be somewhat similar to fibre-optics for light waves,
but scaled to microwave sizes.

So there will be leakage (nothing is perfect)
but the design of the waveguide is intended to minimise this leakage.