Spontaneous headlights starters on 2000 Toyota 4Runner

Found lights turned on spontaneously(after heavy rain/high humidity). Ran car 20 min to charge battery. When turned off, car tried to start(starter sound).

Asked by for the 2000 Toyota 4Runner
Same thing happened to me. I found out what it was when the relay under the hood for the lights was chattering, and ran my battery dead. Replaced the relay (it has three posts) and have had no further trouble.