Simple MetalHeated bed shorted?

I have a simple metal with the printrbot heated bed upgrade. I was cleaning some filament off my nozzle the other day and it fell between the base and bed near the the X-Axis belt. I went to retrieve it with my tweezers and jokingly made a Zzzzpt sound. But to my surprise it actually did spark a little.

Printer still works and has always worked well. Today I grabbed my multimeter and measured for voltage between the aluminum bed and x-Axis guide rod. I found ~12vdc to be there when the heated bed was off and basically nothing when the bed powers on. As mentioned before everything is working great. Is this some sort of induced voltage and normal? Im reluctant to troubleshoot more since it is working fine. I figured I would ask to see if anyone else has this issue.

Edit: I was mistaken the 12VDC is always there even when the heated bed is on.

TLDR: ~12 VDC measured between aluminum bed and chassis.

12VDC measured from Bed to ground on printboard