Can you use a lamp as a cattle prod?

Yes and no. The wiring and metal parts of a lamp may be useful, but the rest of it may be an encumbrance. Also, you can't simply plug it into a wall and have a cattle prod without having a transformer. The key to making a cattle prod is high voltage and low amperage. The standard wall outlet will give you about 25 amps and only 120 volts. That needs to be fixed before you have a cattle prod.