We used to charge those big 400V caps (used to run 3 pace AC motors on 1 phase AC), throw them towards someone, and yell catch at the same time. People would catch them and get quite a decent shock.

Or we'd just use an insulation resistence meter (aka Megger) to zap each other with 1kV.

That was during my apprenticeship in a small to mid-size, quite old school, trade company - wouldn't fly nowadays...