What if you have short sections of metal raceway or armor that don’t connect to something metallic? If they are required to be grounded, connect them to an equipment grounding conductor (EGC) that complies with Sec. 250.134 [250.132]. If they aren’t required to be grounded, is there any reason not to connect them an EGC anyhow?
Methods of Equipment Grounding, Part 1
What Sec. 250.134 tells us about selecting EGC