some tv's, same stuff thats in flurecent lighting. the tubes can hold up to 30,000+ volts with 12+ amps, depending on size. so ya the power is enough to kill and the powder is slightly deadly, not really but can make you sick unless you have other ailments and what not.

But anyways for consequences, id just give you a detention for mischieve. other than that, i wouldnt make a big deal out of it