Harrisburg Pike isn't exactly a galaxy far, far away, but don't tell R2-D2.

If you happen by the post office at 1400 Harrisburg Pike any time this month, you will spot the beloved little droid on the lawn — or at least a U.S. Postal Service collection box made to look like the Stars Wars character.

But the invasion isn't just happening here in Lancaster.

The R2-D2 collection boxes can be found in 200 sites across America as part of a promotional campaign sponsored by the U.S. Postal Service and film company Lucasfilm Ltd.

Mike Hnasko, communications specialist for the Postal Service, said the true purpose of the campaign is a "secret."

"Really, I'm not supposed to say what the mailboxes are for," he said Friday. "But the answer will be revealed Wednesday, March 28."

Members of the U.S. Postal Service in other states already have leaked the "secret" to the press, however.

The R2-D2 collection boxes are teasers for a new stamp that will commemorate the 30th anniversary of the film "Stars Wars."

When the Postal Service and Lucasfilm began to collaborate on the project, it was quickly decided R2-D2 would be the perfect character to represent the campaign.

"R2-D2 already looks like a mailbox," Hnasko said. "I even think he's the same width as a mailbox."

But R2-D2 (or "Artoo" for short) also is a very popular character — and with good reason.

R2-D2 was inducted into the Robot Hall of Fame in 2003 and hailed as a minor hero in the Star Wars universe.

Unlike his partner, C-3PO, who tends to wimp out during a crisis, R2 is decisive and courageous.

"I always liked R2," Hnasko said. "He's a happy little guy. He seems to be a favorite with people."

The U.S. Postal Service employee said he doesn't expect any more spacey surprises before the stamps debut March 28.

"But I'm not sure," he said. "Maybe these R2 collection boxes will start beeping or something.

"Or maybe we'll be invaded by Ewoks. It's all hush-hush."

For more information about the promotion, visit www.uspsjedimaster.com.

E-mail Carla DiFonzo at cdifonzo@lnpnews.com.