Paul Arthur Crafton, the George Washington University professor who has left a trail of mystery from Shippensburg to Switzerland, was released from jail here today after two Pennsylvania judges agreed to reduce his bond to $100,000.

Crafton, accompanied by his wife, Sonia, posted the bond--two cashier's checks for $7,500 and a judgment note for $85,000 against his Potomac, Md., home--and was freed late this afternoon. He was expected to remain here overnight.

The 59-year-old engineering administration professor, jailed since he was arrested 10 days ago in connection with using false identities at two Pennsylvania state colleges, said little during the 15 minutes it took for him and his wife to sign the various court papers.

"I am delighted to be able to go home to my wife and daughter," he said as he left the courthouse, the scene of two days of legal maneuvering to free him.

Crafton is charged with a total of 27 criminal counts in connection with jobs at Millersville State College near here and Shippensburg State College in Cumberland County. Among the charges are theft by deception, tampering with official records and forgery. He had been held on two separate $150,000 cash bonds.

In reducing the bond, Lancaster County Judge Ronald L. Buckwalter said, "The bail set in this case . . . is excessive considering the nonviolent nature of the charges involved."

However, the judge said that "substantial bail may be needed to assure the defendant's appearance" at future court dates.

Cumberland County Judge Harold Sheely, who had scheduled a bond-reduction hearing for Crafton in his own court next week, agreed to today's bail consolidation and reduction.

Other conditions of Crafton's bail require him to report between 8:30 and 9 a.m. every weekday to the Gaithersburg office of the Maryland Division of Probation and Parole and to surrender any passports in his possession. Pennsylvania Deputy Attorney General Kim Daniel said the passports will be sealed by the clerk of the court.

Among the documents Crafton and his wife signed were waivers of rights should the conditions of the bond be violated. Court officials explained that the Craftons automatically would forfeit their house if the professor did not meet all conditions set by the two judges.

In 1982 Montgomery County assessed the value of the house and land at $79,820, according to Lusk's and Sons Ltd. The county does not assess on the basis of the full value of the house.

Daniel, who had argued during a 75-minute bond reduction hearing here Wednesday that Crafton's alleged use of aliases and his extensive international travel indicated he might flee, said after today's action that "we believe Crafton is less of a bail risk now than he was ten days ago."

When he was arrested, Crafton gave the name Anthony Williams and told court officials that he had been born in Idaho and had no formal education, police said.

Daniel said he was satisfied that "appropriate conditions and reporting requirements" had been set to ensure Crafton's appearance at future court dates.

"The bail set by the courts is reasonable," said Pennsylvania Attorney General LeRoy S. Zimmerman.

During Wednesday's hearing Daniel linked Crafton to a tale of intrigue that stretched from New Zealand to Switzerland. Daniel said in court that Crafton apparently used "paper corporations" to arrange international business deals.

Today, John H. Pyfer Jr., Crafton's attorney, described the prosecution's presentation at Wednesday's hearing as "pure innuendo and window dressing."

Prosecutors had said previously that documents taken from an apartment that Crafton maintained here showed he had used 34 names and had taught under several different names at six colleges.

Pyfer said he may challenge the legality of the search warrant used to seize materials from Crafton's apartment on the grounds that it was improperly executed. If the challenge is successful, it could prevent use in trial of evidence obtained there.

Pyfer appeared overjoyed by today's events, which came at the conclusion of a 2 1/2-hour closed conference among Buckwalter, Daniel and himself. "I just don't think you warehouse someone while you are continuing the investigation," he said.

Buckwalter issued his order at 2 p.m. and Crafton arrived at the courthouse from the county jail just before 3:30. When he entered the clerk of the court's office he hugged and kissed his wife.

Pyfer said Crafton would remain overnight in Lancaster because it was too taxing a trip for his daughter, Laura Melanie, who has cerebral palsy.