modulator While everything might appear to earth on the pickguard foil, the source of the earth should be from the bridge itself (there'll the a wire running from bridge somewhere - usually a pot and then earthed from there.)

Foil can tear/wear as pickguard is removed/moved etc. Far more reliable to have the earth's 'hard' wired than trust the foil.

Here are some articles that explain the principles of good grounding (these principles are common to all audio equipment, amps, mixer, guitars, etc.:
http://www.aikenamps.com/index.php/grounding

www.singlecoil.com/docs/shielding_strat.pdf
www.singlecoil.com/docs/shock.pdf
www.singlecoil.com/docs/silent.pdf
I hope this explains it well enough.
PS. I have 5 strats and have not connected the bridge of one of them to ground and they are dead quiet. I have glued a round cut-out of a PC board the back of the volume pots and all ground wires are connected only at this common point.

V8, yes, valid point, as well as the story that eventually the pot nuts will work loose.

Johan, thanks, I shall read all the references. If I understand correctly, the only "exposed" earth connection on your Strats will be the output plug and plate, unless you went with isolated plugs (and cable jacks). So, if you do not earth the strings, what is all the hype about earth to the bridge/strings being a must? Or is it merely to mitigate a side-effect of hum caused by large areas of the guitar (well, the pots at least, as well as the "shield" foil under them, and even the "cavity shielding", if installed) being connected to signal ground in the conventional way of doing it? And what is the story with reducing hum if I earth myself to the strings/bridge? It does not remove the hum, but it reduces it on the one single coil guitar with that problem (I have not yet reached the stage where I clip an earth strap from my pinky to the bridge. Surely, that idea should be to have the lead clipped to somewhere not moving around as much as your playing hand. Even if only for "studio" use. I do occasionally scratch my nose, or pick up the pick, or...) That guitar also displays "static" pops when playing. They tell me it is a single coil thing, but only that guitar does it a lot.

And, then your tone capacitors will not be "shorted" to the relevant tone pot, but will have a wire running directly to your star ground PCB plate?

If you guitar cavities are shielded as per popular DIY fix-it doctrine (I have no plan to do that), do you earth the shield to the PCB as well? I like the idea, as removing all "signal" contact from anything not connecting to the amp makes sense. Maybe a better idea than my ultimately all-over earth bus ground scheme. Would be a shame, I spent some time making up neat brass earth connector plates to fit under the pots. But, before I solder, better to have a "correct" way to connect everything.

https://community.guitartalk.co.za/u/JohanP

Johan, I see in the shielding pdf that the shielding is still connected (via that capacitor) to the star ground. Does this have a negative effect, you mention you do not ground the strings? Why do they connect the shielding to the output? If I do not go the capacitor route, in effect my "star" can be on the shield, not so? Or does the shield still imitate a satellite dish, contaminating the guitar signal?

I put shielding tape on all the inside cavities as this does make a difference. I found this to be the case when building a phono pre-amp where I had to separate the power supply from the circuit board by means of a metal plate as it does reduce interference, it certainly cannot make the situation worse. All shielding is connected to the star ground, but make sure that it is only connected at one point. I separate the shielding of the cavities and that of the pickguard and connect each one separately. I don’t like the idea of the shielding tape folded onto the face of the body to make contact with the shielding on the pickguard as this to me just sounds unreliable.
The output wire from the pickup selector switch goes to the volume control and the output wire from the volume control goes to the centre prong of the output jack. When using the star ground all ground wires are connected at the back of the volume pot pc board. A ground wire from the back of star ground goes to the ground of the output jack (the outer ring of the socket).
The reason why I don’t use the bridge ground wire is because I do not find that I need it and also don’t fancy the idea of accidental electrocution. The reason you would use the parallel connected cap and resistor in series with the ground wire is to protect you from electrocution should there be a problem with the mains supply (and it will if fitted correctly).
You can test the wiring of the venue where you play with a polarity tester:
(http://www.hellermanntyton.co.za/products/elcb-polarity-testers/tel1tlb/911-00148)
I would recommend that you test all mains sockets used at a venue that you are not familiar with. I connect all my equipment to a Furman mains conditioner. Samson also makes similar products. Raru has some and gives you an indication of price.
https://www.furmanpower.com/products/220-240-volt-region-pro-av-commercial
http://www.samsontech.com/samson/products/processors/powerbrite/
https://raru.co.za/musical-instruments/4554475-samson-ps10-powerstrip-rack-mount-distribution-system-230v-black
https://raru.co.za/musical-instruments/4554472-samson-pb10-powerbrite-rack-power-distribution-and-lighting-system-230v-black
After all the power failures that Eskom has had I have connected all my audio equipment to similar power main conditioners. This includes TV’s, Laptops, etc.
I attach a photo of one of my pickguards (the only one I photographed so I can remember what I have done), you can see what I mean by star grounding. The PC board is a treble boost and is attached to the middle pot. The second tone pot I have since changed and is fitted with a 6800pF cap. The tone control also has a pc board glued it and the one end of the cap is connected to this pc board and from there to the star ground at the volume pot. I cut the pc boards discs with a hole cutter 25mm which I happened have for a reason I cannot remember anymore but it looks like this:
https://www.livecopper.co.za/collections/power-tool-accessories/products/high-speed-steel-holesaw?variant=3379706819
I remove the drill bit when cutting the discs. My strats are all not Fender and are all non-standard wiring. All pickguards are fitted with plugs and sockets as on the photo so that it is easy to remove.
I see that you also had a problem with noise (static pops) when touching the pickguard. I had this with one of my guitars with a black pickguard and was wondering if they might use carbon as a colour pigment as this could be somewhat conductive. I would be interested to know what situation is. This guitar is fitted with Lace Holy Grail pickups and a LR Baggs X-Bridge, it turned out that better grounding of the pickguard and a fully charge battery was the answer to the problem.

https://community.guitartalk.co.za/u/JohanP

Thanks, good information.

Terloops, ek geniet daai klein MOD 8 baie!