Personal revelation and experience and anecdote can be valid, instructive, inspiring, and a grand basis for spiritual beliefs or faith... but they hold zero scientific water. Scientifc evidence must be reproducable, and entirely independent of the observer. So far, as a matter largely of faith, but partially of statistics (life exists at one known place in the universe, the laws of physics seem to hold true throughout the universe, the universe is immense, therefore it is likely it exists elsewhere) I believe in extraterrestrial life. But there is not yet any reproduceable, physical (i.e. independant of observer) evidence that they have made it here.

Also, remember Occam's Razor...There are myriad natural and technological sources for lights or unusual objects in the sky, odd mental images, and even physical sensations - all well known and all far less likely to violate current knowledge of physical laws than alien visitation. The simplest explanation is most likely to be correct. The explanation with the fewest requirements for unknown forces is most likely to be correct.
As a skeptic who admires the wonder and surprise of this poorly understood universe, I always eagerly await the next scientific evidence that will completely upset current theories.

Science is damn good fun.