it is the hood switch rubber boot is missing where can get one from

 

Water probably got in the switch without the protective boot. The dealer may only have the exact part, but you can easily find something close and improvise. You'll just have to wire it yourself if the connector doesn't match up.
Or just cut the connector off, toss the switch, hardwire it and forget it. I've never needed a switch to tell me if my hood was open before now anyway.

Let us know what you do to fix it.

 

The switch is not to let you know the hood it open, it's to trigger the alarm if somebody opens the hood to steal the battery or do something else.

Don't toss the switch. Check it first and if it's faulty, replace it with a new one from the dealer.

 

Oh yeah, forgot about that. I've never had an alarm until now. Sorry for the bad advice.