Yeah sounds like an alternator problem. I experienced something similar when driving the company car back to the office on OT. The headlights gradually started to dim, and same thing was happening to the internal lighting for the display dials.
I was close enough to the office when I lost the headlights. Didn't want to get stranded and the car still have power so I tailgated the guy in front and use his lights to guide me. All electricals went dead as I pulled into the office front gate.