I am trying to find the thread that makes the prop - ghostly footprints. The prints that are made out of plastic with led lights in the heel and run by a relay. I need to order that relay. Thank you in advance.
Check with Jeff at Simple Circuit Boards - he made several iterations of the design. I don't think the board is listed on the web site, but he'll know what you're talking about. FWIW, this effect could probably be done with a BS2 OEM microcontroller board (about $35 at Jameco and easy to program). I'd have to check the PWM capabilities of the BS2 before saying for certain, but for simple on-off LED control it would do the job. The dimming could be handled outside of the microcontroller using caps and resistors on the LEDs, much like the original LED chaser circuit hack.
I just finished putting this prop together using led light strips, an Arduino mega and (2) 8x relay boards for the foot prints. I added a second 4x relay board so I could also control the gate on my cemetery. As the "Ghost" walks though my yard the last thing that happens is my gate moves like the ghost past though it. The Arduino and relay boards I bought off eBay cost me about $20 total. Its getting late int he season so you would need to order State side vs. from China so it might cost you more.
The link is to a basic concept of controlling 4 relays from a Arduino Uno. http://www.hobbyist.co.nz/?q=interfacing-relay-modules-to-arduino