Reverse Lights work intermittently coincides with automatic shifter

I have a 1998 Honda CRV. The reverse lights work intermittently. I have discovered it coincides directly with the reverse light on the dashboard which also does light up intermittently. When one is lit the other is lit and also the same when one is not light neither is the other. I can move the shifter up or down a touch to engage the lights but I would still like to know which part this is so that I may repair. I am handy and DIY inclined, but seeking some direction here.

Constants, Reverse functionality at the transmission works at all times .