It does look like a static discharge from an edge in the camera to me. The fact that it starts and stops then starts again says the charge builds, arcs to depletion then repeats the cycle with a slightly different discharge point each time. Might try finding an antistatic wipe that will be safe for the materials in the camera body. Anyone know of one?
I'm familiar with the static effects available in Arizona, having worked there a year at a newspaper in Casa Grande. When rewinding rolls of newsprint from butt rolls to make a bigger roll I'd need to measure the diameter occasionally while running and would draw a two to three inch spark off the frame of the rewinder. What is that, thirty to fifty thousand volts it takes to jump a three inch gap?