Dashboard lights flicker on/off long periods both ways

Have an 1997 Passat (1600cc). The dashboard lights flicker on and off for long periods and short periods. Particularly frustrating at night time when driving. Headlights and external lighting are not affected. Internal indicator lights are affected. For example: Cigarette lighter indicator light, back window heater light indicator. In addition I noticed that the internal driving indicator lights when activated cause the dashboard lights to flicker on and off also. Any help - much appreciated