Unauthorised Moving 787 ground test switch
 

Had a pilot (unaware of whether engineers were working on the aircraft) move the ground test switch from enable back to normal.

There were engineers working on the aircraft but his response afterwards was that there would have been no problem anyway as the flying controls would have been locked out to prevent any unwanted control surface movement.

Anyone have any info on What tests is that switch used for, is he right that there is no chance of someone potentially getting hurt?

The ground test enable switch is just that - it is part of the logic that the various systems use to enable them going into the 'ground test' mode (it's generally not the only inhibit - safety critical systems will also have air/ground and/or airspeed inhibits).
Flipping the switch to NORM wouldn't result in an unsafe situation, but it could really upset anyone who was actually running a test at the time...

Not unsafe at all. Annoying at most if there were software tests running at the time.

If it was safety critical, it would be tagged.

The ground test switch is used to remove protections rather than apply them. Moving the test switch to Normal is safe but possibly frustrating for the tester, as noted above.

Until it is proven that the movement of said switch DOESN'T pose a safety risk, under all circumstances, no matter how remote, IMO, this is an issue.

Especially, with the shear number of inter-connected systems aboard modern aircraft.