This is all such useful and extremely important information, as it directly relates to personal safety. I am very grateful for all of the effort you are making to reply and to help me. Thank you.
Though I am still lacking in SMPS learning, I recently realized that SM designs carry very high voltage. That is part of the reason that I began to build up an isolated AC supply.
Then, it occurred to me that SM designs are in most all modern electronic devices... including innocent looking small wall warts. I was so moved/freightened that I wrote to my DIY buddies and cautioned them, passionately, to get the needed safety equipment... Meaning, the components of an AC power supply, etc.
I even built an e-cap stinger, for one of them that is less electronics oriented, because he often repairs air conditioners. Air conditioner e-caps are very mean animals.
I also upgraded my personal DIY e-cap stinger... I simply added high ohms and wattage resistors across the lead inputs of a cheap multimeter. Now, even though the voltage readout values are wrong, I can at least see when the voltage reads zero. I added caution labels, so the meter does not get used for other purposes. And, I know not to use it for super high voltages, because of the cheap leads, glass fuses and lack of impact bracing. But, it is somewhat better than nothing and I have a proper Brymen 869s, for the more dangerous situations.
As I write this, it comes to mind that I could make an adapter for my Brymen. Just a double banana male to female connector with the needed resistors connected across the posts... Plug the adapter into the meter and the leads into the adapter. I would need to encapsulate the resistors, for explosion protection, but the other robust protections already built into the meter would then be in play. Hmm... I just high-jacked my own thread. lol