[2sheep]

Seriously, this sounds like ball lightening which is well documented.  There is a lot of interest in such phenomena by people who are seriously searching for alternative energy sources such as retired professor of electrical engineering, Dr. Gary L. Johnson.  See at http://www.eece.ksu.edu/~gjohnson/

[2sheep]

Google Search: "ball lightning" -- 17,500 hits.  Top two:

 Ball Lightning -- BALL LIGHTNING does not look like "lightning." Instead, it usually appears as a mysterious glowing sphere which drifts through the air. It is typically the size of a grapefruit, but sometimes appears as small as a pea, or as large as a bus. It sometimes drifts through the air, but can also bounce along the ground. It usually lasts only a few seconds, but sometimes persists much longer. Various colors of "BL" have been seen, sometimes it changes colors, and sometimes it has internal structures such as layers or moving sparks. Most researchers agree that it is real, yet its nature is still highly controversial, and no sensible theories yet exist to explain it.

 Ball Lightning

 Unusual Phenomea Reports: Ball Lightning

[BlackJack]

Great Balls o' Fire! Thats it. More power Scotty!

[brat]

I thought it sounded like ball lightening too. Bizarre.