if your blinker light switch wont self cancel, you dont need a new switch there are 2 wire springs on the switch that eventually will break , these are colored differently and still available from holden for a few dollars
true that. be careful to clean and shavings and crap out while you are in there and if need be re-lube with the right stuff.
While it is usully the springs that go first, its often not long before other parts of the same mechanism start to break down as well, so keep in mind it may need to be replaced as a unit in the near future. (dont replace with cheap ones either - go genuine)