Arnold Warshawsky remembers dropping his check in the mailbox on the Pentagon concourse. What baffles the 35-year-old Army major is how the $50 check, bound for his synagogue in Alexandria, wound up in the coffers of Rex Humbard, the Ohio-based granddaddy of Christian TV evangelists.

The mystery began last fall when Warshawsky received a notice from Agudas Achim Congregation saying he hadn't paid his dues.

"I didn't think much about it," said Warshawsky, "until my bank statement arrived." Warshawsky noticed that among the cancelled checks was one he had written to cover his monthly dues. On the back of the check was typed "Pay to the Order of Rex Humbard." Underneath that someone had misspelled the syngagogue's name, calling it "Agudos Ochim."

"I called the treasurer of the synagogue right away and said I didn't understand why it was signed over to the Rex Humbard Foundation," said Warshawsky, who lives in Springfield.

Neither did treasurer Neil Ainsfield.

"I don't know if we ever received the check," said Ainsfield, but he recalled an equally strange occurrence around the time Warshawsky's check went astray.

The rabbi was handing out wrapped pencils and candy to the children after Friday night services, Ainsfield said, when some parents noticed that instead of the name of the conservative temple, "the pencils said 'Jesus Saves' and other things you wouldn't see in a temple."

"I don't know if we've had some strange visitors or what," said Ainsfield, of the synagogue whose membership includes 375 families. "But we didn't find anything stolen and nothing has happened to the other checks."

Last December Warshawsky wrote to his bank in El Paso and sent a letter to the Akron-based Humbard Foundation, requesting a $50 refund. The original check had been deposited two weeks after Warshawsky wrote it in Humbard's account at the Bancohio National Bank.

"I have no earthy idea how anything like that could happen," Jim Dailey, a spokesman for the Humbard Foundation, said last week. "Of course, we get thousands of checks made out to us every day and we cash them."

In January Warshawsky received a "Dear Arnold" letter from "Your TV pastor, Rex Humbard" expressing "Greetings in the name of our wonderful Lord and Saviour, Jesus Christ." Humbard, whose name was affixed to the letter with a rubber stamp, apologized for the mistake and assured Warshawsky he would receive a refund within two weeks.

When six weeks passed without a refund, Warshawsky fired off another letter to Humbard and asked bank authorities to try to recover the forged check.

Warshawsky heard nothing until early last week when he received a three-page form letter from the man whose religious broadcasts and "You Are Loved" motto are beamed to millions worldwide.

"I know that you are facing another time of need," wrote Humbard, who reminded Warshawsky of "the time I've set aside to pray for you, Arnold." The letter exhorted Warshawsky to mail Humbard a special prayer request form.

The following day Warshawsky's $50 refund check, dated Jan. 23 but postmarked April 3, arrived.

"The whole thing is really galling," said Warshawsky. "Now I'm afraid I'm on their mailing list for good."