Can you get away with not shielding an electric guitar?
This is an electric guitar subject you're not supposed to talk about, but I'm talking about it.
Over many years it has been pounded in our brains that for any, and I mean any electric guitar, it must be shielded. No ifs, ands or buts about it...
...but do you have to?
Before answering that, there are guitar players that "build" (as in part together) guitars and never bother shielding the electronics. Is that due to not knowing how to do it? No, because shielding is easy. Is it due to cost? No, because copper shielding tape is cheap. Is it due to laziness? Also a no.
The main reason some don't shield is because it can alter the way the pickups sound.
Truth be told, if your solder connections are done properly, your cable management is in order, your output jack is a Switchcraft, the grounding is good, and you're using thicker modern wiring (as in formvar coated wires, a thermoplastic resin, and not cloth coated stuff)... you may in fact be able to get away with no shielding at all.
Does this mean you will end up with a guitar that has massive amounts of electronics buzzing?
A good example of this are entry level Squier Bullet Strat guitars. Yes, they are shielded, but just barely. Many of them only have cheap shielding tape covering the volume pots and maybe the pickup selector with no conductive shielding paint in the electronics cavities whatsoever.
For the ones with a humbucker pickup on the bridge side, I seriously doubt you would hear much more electronics noise if you simply removed the shielding entirely since there's barely any to begin with. The single-coil pickups would most likely blast out electronics noise, but the humbucker would probably still sound okay without too much noise. Or at least okay for a dirt cheap humbucker pickup.
Is there truly a difference in tone when the electronics are not shielded?
Some guitar (and bass) players swear that the "purest" tone you can get is when there is no shielding and the pickup is wired directly to the output jack. Yes, I mean no tone control, no volume control. When you plug in, that guitar or bass is "always on 10" all the time. If you want volume control, you would have to use a volume pedal.
Guys who put together guitars and basses this way sincerely believe that anything interrupting the signal, which they believe includes shielding, takes away articulation from the pickup. And what that means is the belief that shielding somehow "disconnects" the pickup from outputting its true potential, so to speak.
Then there are other guys who put together a more standardized electronics setup with volume and tone controls, add the shielding, and the guitar to their ears doesn't sound right. The shielding is removed, and they hear a positive difference in tone, so they just leave the guitar that way.
Am I brave enough to no-shield it?
With a single-coil Strat, no.
However, I have entertained the idea of parting together a two-humbucker guitar.
I play mostly clean tones these days, and it would be interesting to see if not shielding the instrument at all would result in something I'd enjoy playing.
Would I do the wired-direct-to-output-jack thing? No. I like having volume and tone controls. But I would wire mine in a minimalist way. Two pickups, one pickup switch, one volume, one tone.
And if with no shielding it blasted out noise, well, that's not really a problem since I can just add shielding to quiet things down.
Remember that shielding is never mandatory. If parting a guitar together (particularly with humbucker pickups), try it without shielding first as it might work for you. If not and things get too noisy, add the shielding in.