Here's what I think some other warnings should look like. Those are more akin to the warnings you see on products and in product manuals and use similar graphics and phrasing. I expected those will be dismissed as rubbish red tape by some experienced repair technicians but they are not the target, the target is someone inexperienced, probably a kid who stumbles across this wiki trying to fix a game console who has no clue what they're doing along with any lawyers and government regulators.
If you're happy with those I'll write the template code for them later this week.
Large banner div warnings
Those should only be necessary to put those on guide pages that directly give safety advice about a topic (example)
DANGER Pyrotechnic devices contain potentially lethal hazards or can become lethal hazards if not correctly repaired which will result in death or serious injury. Ensure you fully understand the content of this page before attempting to dissemble or repair a Pyrotechnic device. Do not attempt to dissemble or repair a Pyrotechnic device unless you understand how to do so safely.
WARNING Mains powered devices contain potentially lethal hazards or can become lethal hazards if not correctly repaired which may result in death or serious injury. Ensure you fully understand the content of this page before attempting to dissemble or repair a mains powered device. Do not attempt to dissemble or repair a mains powered device unless you understand how to do so safely.
CAUTION Lithium Polymer cells are potentially hazardous and can present a serious fire hazard which may result in serious injury or property damage. Ensure you fully understand the content of this page before attempting to disassemble or repair a Lithium Polymer battery. Do not attempt to dissemble or repair a Lithium Polymer battery unless you understand how to do so safely.
NOTE The content of this Wiki is community contributed and as such no guarantees that this information is accurate or applicable can be made. Caps Wiki and its owner/operator and contributors assume no liability for actions taken based on this information.
Medium box warnings
Those could probably be put at the top of the disassembly notes or in an infobox under the device infobox on the right hand side of the page. (example)
DANGER This device has exposed high voltage and intentionally defeats earth leakage circuit breakers.
DANGER Capacitor C5 is 2 kV 125 μF (300 J).
WARNING Those 450 V capacitors do not have bleeder resistors.
CAUTION This heatsink has very sharp edges.
NOTE The sensor window is extremely fragile.