Who Measures Up to Michael J.?

What could be better/cuter than one Michael J. Fox? How about two ! That’ll be the gimmick in a soon-to-shoot Diet Pepsi commercial.

But . . . Fox won’t be playing both roles. One of the “Foxes” will be a body double, wearing a “life mask” created by special effects meister Rob Bottin (“The Thing,” “RoboCop”).

Casting reps are now in search of that body double--who can be male or female, but must resemble Fox physically.

In fact, reports a source, the fake Fox must have the real Fox’s exact body measurements. We’re not just talking 5-foot-4 (to 5-foot-4 1/2), 120 pounds. There’s also the requisite 28-inch waist, 33-inch chest--and a 23-inch head!

Plus: shoulder-to-shoulder (seam-to-seam) measurement of 15 inches and waist-to-floor (that’s the outseam) of 37 1/2 inches.

When will we see the two Michael J. Foxes? “It’s part of our ’89 ad campaign,” said a Diet Pepsi rep. “Since we like the element of surprise, I can’t tell you exactly when it will air, but . . . we have been known to debut some of our commercials during the Super Bowl.”

While on the subject of body doubles: Mimi Rogers (a.k.a. Mrs. Tom Cruise) will have one for the now-filming “Hider in the House,” for Vestron Pics. (Matthew Patrick is directing in and around Los Angeles; Gary Busey co-stars.)

Nudity is required. So is the following: height, 5-foot-8; leggy, with “thin thighs.”

And, reports a source, a size 36 bust “with a C or D cup.”

Shoulder-length auburn or reddish hair would help.