Was this likely a problem with the alternator?

I know someone was just staring at my profile, waiting for my 1,001st car question lol.

I saw a utility van driving down the road during overcast and their headlights were flashing. I know it wasn’t being done manually because it was at a steady, continuous pace and because the lights would slowly fade on instead of just turning back on.

In other words, they would turn off, then fade into the “on” state, and repeat, at a rate of about twice per second.