ELI5: Why are lights sometimes seen in sky before an earthquake?

I've seen multiple accounts of strange lights being seen in the sky before an earthquake. Wiki describes this as: " An earthquake light is a luminous aerial phenomenon that reportedly appears in the sky at or near areas of tectonic stress, seismic activity, or volcanic eruptions". From what I have read, the light may more usually appear immediately before an event, but is sometimes reported several hours or even days before. is there an explanation for this phenomenon?