Quoted from mot:I'm a purist, so my only Monster Bash mods are a ColorDMD, sillyoldelf side art, and one more that no one has mentioned that I LOVE!
http://www.pinbits.com/index.php?main_page=product_info&products_id=387
The WPC-95 power driver board removed CPU control from two strands of general illumination and made them 'always on'. These are used behind the translight. The only obvious reason this was done was to save money, but I think it really hurts the light shows.
The Pinbits Blackout board board switches these two strands of GI off when the lower playfield strand shuts off, and it enhances the light shows immensely! When Frankenstein multiball begins, all the lights shut off. At the end of the game, after the match sequence, all of the GI shuts off as the flashers go crazy. It's the best.
If this mod is sold out, you can also get a GIOCD which is designed for a totally different purpose, but additionally performs the same effect as the Pinbits board when set up for WPC95. Highly recommended