A Salvadoran airline and Rep. Frank R. Wolf (R-Va.) have arranged for a Cambodian social worker from Arlington to travel free to San Salvador next week to escort home a refugee who ended up in a jail there after he set out to walk to Cambodia.

Wolf said yesterday he also had sent a cable to the U.S. Embassy in San Salvador asking for help in facilitating 27-year-old Tith Plok's trip back to Arlington.

Plok, whose parents believe him to be mentally retarded, left Arlington in September. He had said he wanted to walk to Cambodia, where he mistakenly believed his family was living.

He was jailed in San Salvador because he was without identification papers.

Refugee workers in Arlington have been trying to raise money for plane tickets for Plok and a social worker, Sowatha Kong, who they said will be sent to convince him that his family is in Northern Virginia and to escort him home.

TACA International Airlines has agreed to provide the tickets free "to demonstrate the good will of TACA and the need to get TACA some roots up here," said John Mullenholz, the airline's attorney in Washington.

Kong said yesterday she will leave when her visa request is granted, probably next week.