John, I'm not certain, but I think some of the lights documented in the articles linked by Mike are for precursory lights. About 20 years ago, a seismologist gave a talk at UCSB where he basically accepted that these occurred but did not believe the Greek VAN electric prediction method (telluric currents??).

I questioned Bob's report for Northridge because I had not heard it...or heard it (maybe here) and forgot it.
Chris