A few questions regarding B/E-fields in practical circuitry
If by "electricity" you mean "joules of electrical energy" then yes, "electricity" is nothing but concentrated e-fields and b-fields.  It's the same thing as audio and video signals traveling along coax cables.  With wires, the energy can leap along a column of mobile charge carriers, while the charge carriers themselves only wiggle back and forth.

Plastic insulated lamp cord?  Yes, the plastic would tend to concentrate the e-field between the wires.  It would also change the speed at which the EM energy moves along.  But mostly the fields are concentrated by having the two wires placed very close together.  That's basically how Ethernet "twisted pair" cables work.  The wires behave like the two plates of a capacitor, or like a very stretched-out single-turn inductor.  Where are the strong fields in a capacitor?  Between the plates.  And in an inductor?  In the donut-hole.

But wire-pairs are very good at guiding EM energy, and the usual losses aren't from radiation.  The EM fields don't leave the wires and fly off into space.  Instead the losses are "frictional," from the ohms of the metal (and perhaps from high-freq dielectric losses in the plastic.)

A leaping spark is not a jumping of EM energy.  After all, a spark is a resistor, the carriers in the plasma aren't flowing near velocity c, and the EM energy actually flows inwards into the spark from all directions.



Note that this article was written based on the following idea: explain the material in undergrad physics texts to the general public wo/relying on equations.  Pull a Feynman, Red-book style.  Sit kids down and say "look, this is how it really works."  Oddly, the correct EM description of simple circuits is really only taught in undergrad fields/waves courses, antenna design engineering texts, etc., but rarely mentioned in circuit design courses.  We all pretend that amperes equals watts, and pretend that energy flows inside the metal.  Nope, wrong.

So I took the basic EM info, stripped out the math, and described it using words and some field diagrams.  The Poynting diagram shows us the location of the flowing joules.  The central idea is simple: descriptions of EM waves propagating on a 2-wire waveguide are identical to descriptions of simple circuits, since 2-wire waveguides have no boundary in low frequency, and the math works fine all the way down to DC.  As far as I know, no textbook author ever tried this in K12 books.  If you haven't encountered it before, it looks very weird  ...and many of us haven't encountered it before.  (JD Kraus does a bit of it in his text "Electromagnetics," but even most fields/waves texts avoid Poynting and pictures, and stick with the math.)

An HF transmitter sending RF wattage along a conductor pair to a distant dummy load?  That's identical to a 60HZ generator powering an electric heater.  Or instead use a battery and a light bulb, and it's no different: the energy isn't inside the electrons or trapped within the metal.

Won't this be confusing to kids?  YES!  This isn't for classroom work.  You shouldn't be trying to memorize it for exams.  Instead it's for anyone who thinks that basic electricity is contradictory and confusing, or thinks that grade-K12 books aren't giving the straight story.  I've repeatedly discovered that many of the contradictions are caused by simple physics info which is declared "too advanced" and left out.