A writer of mystery novels might have called it "The Case of the Two Wandas."

Wanda Marie Johnson, who lives in Adelphi in Prince George's County and works as a baggage clerk at Union Station, described it as two years of mounting confusion and frustration.

Wanda Marie Johnson, who lives in Suitland in Prince George's County and works as a nurse at D.C. General Hospital, was blissfully unaware of all that. She did not know about the other Wanda until reporter called her and described the amazing coincidences.

Both Wanda Marie Johnsons were born on the same day - June 15, 1953. Both are former District of Columbia residents who moved to Prince George's. Both are mothers of two children. Both are owners of 1977 two-door Ford Granadas.

The 11-digit serial numbers on their Granadas are the same except for the last three digits. Worst of all, their Maryland driver's licenses were identical because a computer determines each license's number by name and birthdate - and, in the cases of the two Wandas, they were the same.

As a result, Wandas Marie Johnson of Adelphi found herself the victim of medical record mix-ups, harrassment for payment of a debt she didn't owe, telephone calls from strangers, and a misunderstanding with Maryland motor vehicle oficials, who insisted that she wear glasses while driving.

It was the other Wanda who wears glasses.

It all became so troublesome for Wanda Marie Johnson of Adelphi that she sought frantically to find the other Wanda. "People I talked to thought I was crazy," she said, and she began wondering about that herself.

Her problems began while both women still lived in the District - one at 1006 Girard St. NW (she was the one who later moved to Adelphi) and the other at 901 New Jersey Ave. NW.

They both had babies at Howard University Hospital and attended a Howard clinic then located at 16th Street and Park Road NW.

It was there that the Wanda on Gerard Street discovered something was wrong when doctors at the clinic began consulting with her while using the other Wanda's medical information. A Howard University official confirmed the existence of the two sets of Wanda Marie Johnson patient records and said they were identified by address and Social Security numbers, which "are very close." (The first four numbers of their nine-digit social security numbers, are identical.)

In the latter part of 1975, the Girard street resident moved to Adelphi, only to be followed into Prince George's by the other Wanda who moved to Suitland.

The Adelphi Wanda has two daughters, but she got a hospital bill for the birth of a son (the Suitland Wanda has two sons). Later she received calls from strangers asking, "Didn't you say you were Wanda Johnson?"

Then, last December, a credit company threatened to sue Adelphi Wanda for nonpayment of a bill for furniture that Wanda and Michael Johnson of Suitland had bought. The Adelphi Wanda didn't even have an account at the store, but that did not satisfy the bill collector who had heard stories like that before.

"Are you trying to say your name isn't Wanda Johnson?" the creditor asked.

"No," she said.

"Are you trying to say your birthdate isn't June 15, 1953?"

"No."

"Are you trying to tell me you don't work at Union Station?"

"No. I'm just saying that's not me," she replied weakly.

"Oh, come on, Miss Johnson!"

"Well, who's Michael?" she asked. "And what did I buy?"

"You and michael came in here and bought furnitture and you tell me you don't know what you bought? What do you take me for, a fool?"

In fact, Wanda and Michael Johnson of Suitland had already paid the bill. But crisscrossed home addresses, the identical names and birthdates, and the skepticism of the creditors confused the issue for several weeks more.

The Adelphi Wanda learned to drive in 1977 and bought her Granada. But each time she tried to apply for a Maryland drivers permit and registration she was told she already had a license with a restriction requiring her to wear glasses.

"I've never worn glasses," she protested to the skeptical official. "That's not me."

More vehicles personnel instructed her to call their office in Glen Burnie with her "other Wanda" story. "I had to speak to four supervisors before I got that straightened out," she said, shaking her head.

A few days later the Adelphi Wanda received the other Wanda's driver's registration. Her own followed three days later.

The Maryland Motor Vehicles Department said the computer had inadvertantly changed the Suitland Wanda's address to the Adelphi Wanda's address. Identical names do arise from time to time, said an official of the agency.

But, he added, "I've been here 15 years but this is the first time I've ever seen this kind of problem arise. I can't recall a situation where two people had identical names, identical dates of birth and then a computer made an error and changed the address of one of them."

At one point, Michael Johnson, the Suitland Wanda's husband, went to the motor vehicles office to locate her missing registration.

They told me they sent it Adelphi, Maryland," he recalled. "I told them, 'We don't live in Adelphi!' They said 'Are you sure? I said, 'Of course, I'm sure.'"

In still another incredible coincidence, Michael Johnson also works at Union Station. He once even worked in the baggage department with the Adelphi Wanda, and he knows her and her boyfriend. But the two Wandas themselves had never met and Michael Johnson never knew the Adelphi Wanda was being confused with his wife.

Upon learning about this from the reporter, the Adelphi Wanda remembered that Michael Johnson and her boyfriend used to joke "that all Wandas are alike," Yet neither one knew how close they were to the truth.

The two Wandas finally met through a reporter to whom the Adelphi Wanda had told her story, the other day at Union Station.After a pause, the Adelphi Wanda asked, "what do I say to myself?"

The Adelphi Wanda is a lively outgoing person with a passion for crossword puzzles and a chronic case of "Saturday night fever." The Suitland Wanda has a quite, reposed manner, nurtured by her love for sewing and mystery reading.

Appearances define them further. The Adelphi Wanda stands five feet three, the other five feet five. The Suitland Wanda wears glasses the other does not.