I recently obtained a "Violet Wand" (not to be confused with a "Violent Wand" which is what Harry Potter fans use when you make fun of them).
It was made over 80 years ago, and still works. It's a nice example of applied physics, and ALSO how some will try to scam you into buying quack medical devices claiming to cure almost every known disease. Perfect for Slightly-Mad Science.
Time for some antique high voltage!

For more information regarding Violet Wands:
Wikipedia http://en.wikipedia.org/wiki/Violet_wand
Museum of Quackery http://www.museumofquackery.com/devices/uv.htm
Wacky "Energy Therapy" People http://www.meridianinstitute.com/eaem/master1/mastcont.html

Links regarding quack medicine:
Quackwatch http://www.quackwatch.com
Respectful Insolence http://scienceblogs.com/insolence/skepticismcritical_thinking/friday_woo/
Quack Medicine http://www.quackmedicine.com/