Butch Patrick, aka ‘Eddie Munster,’ to greet McHenry Outdoor Theatre visitors

At first, when the man on the other end of the phone introduced himself as Eddie Munster, Scott Dehn thought it was a prank.

“I almost hung up on him,” said Dehn, owner of the McHenry Outdoor Theater. “I thought that my dad was playing a trick on me.”

But it was no joke. It was, in fact, Butch Patrick on the line. Patrick — a child actor who rocketed to stardom portraying the young Eddie Munster on the hugely popular 1960s show “The Munsters” — had a proposal for Dehn.

Patrick is testing the waters for a planned collaboration with outdoor theaters nationwide, and said he’d like to do an appearance at the McHenry Outdoor in conjunction with his concept.

So get excited, Munsters fans: He’ll do just that on Wednesday, Aug. 14.

“He’s on a mission to help outdoor theaters not only survive but also thrive,” Dehn said of Patrick in a news release. “We’re going to have a lot of fun with this. We’ll have live music, some vendors selling related merch — and we’ll feature “Munster, Go Home!” as well as “The Addams Family.”

The fun will begin about 6:30 p.m. at the theater, 1510 Chapel Hill Road, just outside McHenry.

Those attending are encouraged to dress as Eddie Munster or Wednesday Addams. There will be a costume contest with a top prize of $100 each for the best two lookalikes – plus a pair of gold passes to the Volo Museum, granting access to both the museum and Jurassic Gardens.

Those in attendance also will get to see one of the Volo Museum’s latest acquisitions.

“What a crazy coincidence,” said Jim Wojdyla, marketing director for the museum. “Just today [Aug. 2] we acquired Eddie’s Go Cart from the show. It’s the only one in existence.”

Wojdyla said he looks forward to having Patrick climb in and sign the go cart at the Outdoor Theater Aug. 14.

Patrick, who grew up in rural Illinois and Missouri, said he already has visited a couple of Iowa drive-ins testing the waters for his idea of packaging double features from old public domain films created in the 1930s, ’40s and ’50s.

The films he’s targeting were among the first fare featured at outdoor theaters that once numbered about 4,000 in the nation, and now number fewer than 400. Enjoying films at outdoor theaters is something that Patrick, who celebrated his 71st birthday Aug. 2, affectionately recalls from his own youth.

“These theaters are part of Americana,” he said. “If you were lucky enough to have gone when you were a kid, you remember it fondly.”

Patrick said he hopes to help theaters improve their midweek attendance with nostalgic films and possibly “stars and cars” appearances. The aim, he said, is to see the nation’s remaining outdoor theaters not only continue to exist, but also to prosper.

“You can stream a movie at home. You can go to a multiplex,” Patrick said. “There are a lot of ways to experience a movie. But there’s only one way to experience a drive-in, and that’s to physically go out to one. I hope to meet a lot of McHenry Outdoor fans on Aug. 14.”

The meet-and-greet, live music and more will be included with the regular price of theater admission, which is $14 for adults, and $8 for military and those ages 60 and older, as well as for children ages 3 to 11. Those younger than 3 are admitted free. Anyone who has recently visited the Volo Museum can exchange their wristband for a free popcorn at the theater. Those visiting the theater also can get $2 off entry to the Volo Museum by presenting their theater ticket stub.

Additional information about McHenry Outdoor Theater is at the theater, visit goldenagecinemas.com. More about Volo Museum can be found at volofun.com.