But laptop chargers _do_ have transformers, and inductors for that matter -- they're switching power supplies! I actually had a problem with this on my MacBook to the degree that I would simply connect a wire between the protective earth and a radiator I had. It worked, strangely enough. It's also perfectly safe to do.
I stand corrected, the power supplies you find for electronics do have transformers in them that provide galvanic isolation.
I guess I’ve spent too much time looking at high voltage (measured in kV) power electronics used in HVDC transmission, it didn’t occur to me that household electronics would use a slightly different approach.
