This here is the Volt family.

Marty volt is small and so he can jump across a small stream. Put up a small net and it’s impossible for him

Victor, though. He’s got some strong legs. He can jump the net and the stream.

In fact, he’s so strong he can jump over a small river but not if you put a small wall across the way. Then, even with a running jump, he’ll be blocked.

And finally there’s Kal, ahem, Clark Volt. He’s super strong. So strong it could be an ocean and with a little jaunt before leaping he’d jump it.

The stronger the volt, the further they can go and the bigger the obstacle you need to make it impossible for them to make it.

So high enough voltage can literally leap through air (that’s the arcing you see in power plants shorting or lightning) or even wood itself. Even rubber, with a high enough voltage, will be conductive since the sheer force of the current will find a path for the charge.

That’s also why we have lighting rods, it’s easier to redirect the current to a safe spot made to handle it than to try and make high skyscrapers out of a material that can resist the insane charges of lightning and still be strong enough and light enough to build with.