HERE’S the latest CBS ploy to make Laurence Fish burne more palatable to the “CSI” audience: a major crossover event spanning all three hit series.

Set to take place one week during November sweeps, the three-episode story arc will find Fishburne’s “CSI” character, Dr. Raymond Langston, leaving his comfy Las Vegas Crime Lab environs for a case that takes him to Miami, where he’ll collaborate with the folks on a Monday-night episode of “CSI: Miami.”

From there, he’ll fly north in time to appear in Wednesday night’s “CSI: NY” episode and then head back West — to wrap up the case at CSI’s Vegas HQ on Thursday.

Details about the storylines have yet to be announced.

It will be the first time that the “CSI” franchise has ever done a crossover that involves all three of the series at the same time. As The Post reported earlier this week, CBS announced that Langston, a former professor, will be loosening up this season in an effort to woo back “CSI” viewers lost as the veteran show’s ratings dropped last season.

Langston will ditch the straight-laced suit-and-tie combo to reflect the fact that he’s getting accustomed to his new gig.

The focus on Langston, called in as a replacement for beloved “CSI” Gil Grissom (William Petersen) last season, is part of the network’s efforts to change fan opinion about Fishburne.

His introduction to the “CSI” cast didn’t go over well with viewers after Grissom’s departure in January.