In college I stripped one end of an Ethernet cord and plugged it into household current. The other end I had hooked up to an old laptop I no longer wanted. The wire exploded, and the motherboard was fried. YMMV. Laptop was an old Sony Vaio c. 2001 vintage if it makes a difference.

(On the plus side, this made up for sleeping through that physics class where my professor did the exploding wires demo.)