2006 Toyota Highlander won't turn over after getting wet

The clicking noise you hear is the starter solenoid. It is clicking because the battery is not supplying enough voltage to turn the starter. The battery may still be strong enough to operate the lamps, but not enough to turn the starter. This could be due to a weak or faulty battery or even a poor connection somewhere in the battery cables. You might try disconnecting the battery cables and cleaning the connections. You could get the car jump started with a set of jumper cables and another vehicle or you could take the battery out and bring it to some place like AUTO ZONE or Wal-Mart to have it recharged and tested. If it is not a bad battery, then you need to find out what caused it to have a low charge. That might be as simple as a light left on over night or could be due to a faulty alternator or charging system problem.