[Slightly on-topic tip:] Use a sliver metallic Sharpie to label all of the cords. I even label the ends of the power cords that are attached to the device, such as TV, DVD player, cable box, etc… because they plug into a power strip in the cabinet that they all sit on top of. For some reason, AC adaptors rarely have even the name of the manufacturer of the device that they go to, much less the name of the device itself.
They have isolation transformers, but they’re much smaller than the ones used in linear supplies. This is because the switching frequency is very high.