Anyone who believes a word of this rant will be in immediate risk of death through electrocution. You have been warned.
You are up against the Elf'n'Safety fruitcakes here. Originally there were no regulations and working people accidentally sawing through cables electrocuted themselves. Then industry was compelled to put every live conductor either out of reach or inside a steel conduit. Then they decided there should be domestic regulation and they hit a big snag, steel conduit was not credible.
If you compel someone to earth their electric cooker you might simply be providing a return path for the electricity thus completing the circuit and killing someone. A poor ground connection can save your life. So they floundered about then settled for the 25mA residual current breaker (RCB). You really want one of these in the circuit so let's not start sinking earth spikes.
The RCB is a sort of transformer, there are a couple of windings to take the current out to the cooker, a couple of windings to bring it back. These two windings go in opposite directions so they should cancel each other out. If they don't cancel each other out it is assumed that some of the current is leaking to ground, possibly through you, and the breaker opens the circuit to save your life. Test showed it took more than 25mA to off you hence the leakage limit.
Let's now consider the poor unfortunate making the laser who has to try and be CE compliant. ie: it mustn't interfere with your telly. You might think that putting it close to the telly would reveal all, but of course the standard is for telly's of yesteryear which used to be analogue. When things get CE tested for emissions they usually fail because testing is expensive and the tester can make more money if you flunk. So what they do is bung on the CE sticker, add the occasional ferrite to the power lines and waffle on about earth connections in the manual.
This is what you are reading and getting worried about. What you really need is a bit of info about Faraday cages, earth loops and how to get data lines into/out of a cage. Anywhere the 25000V laser PSU might leak wants to be within 1" of the earthed case and your fingers must not be closer than that when it is switched on. /rant