I was going through some of my parts and found this...it came out of a 2500 set.
It's a small, 1 inch by 2 inch orange rectangular box with a white and green wire. Inside are a couple resistors, a diode, and a spring.
The top is marked 840364202 8-81.
If I could find my camera, I would take a picture
Hopefully someone can help me out.
Thanks!