Your handlebar switch (made by either Aprilia or CEV?) is still available (I can refer you to a couple of sources if you find you need one) but you will have to pay quite a bit for one. The switch is removed by removing the two screws in the top. But I would refer to your wiring diagram first and confirm that everything is good there (continuity) and also make sure your light bulbs are not burnt out. Is the bike charging your battery properly? Do you have a separate turn signal switch?