There is usually an accompanying indication if its a signal bulb. That can be defeated by disconnecting both front and rear brake switches, like we do for track bodywork, and it will go away when you restart.
Mine dropped an O2 sensor early this year. That will throw the light.
Kind of a slight divergence to the topic...if one had a TuneBoy, would it be possible, through a WiFi connection and the LogWorks app, to read a check engine code?
I actually hooked up the Tuneboy to my GMC Envoy, read a code, and cleared it. Does the Ducati's USBish connection support OBD II protocols?