Calvin Gurley, an unemployed auditor with $500 of his own money in his campaign war chest, yesterday announced his candidacy for mayor of the District of Columbia, saying he would run as an independent to put the reins of the city government back in the hands of a lifelong Washingtonian.

Gurley's campaign announcement contrasted sharply with the well-orchestrated kickoffs of veteran campaigners, who generally try to surround themselves with as many supporters as possible to show momentum.

Gurley, 32, made his announcement in the basement of Mount Horeb Baptist Church on Bladensburg Road NE during a community meeting of residents of Fort Lincoln, with one supporter and one reporter present. Several residents first said they had not known that a candidate and a reporter would be at their meeting and expressed their neutrality in the race.

The new candidate, whose lists his last job as tax auditor in the D.C. Department of Finance and Revenue from March to September 1985, pointed to recent problems in the city's prison system and housing department as well as revelations of wrongdoing among top city officials as evidence of loss of control by Mayor Marion Barry.

"It's a decaying of the mayor's leadership," Gurley said in an interview. "People have voiced to me that this city needs a new leader and role model."

He said he plans a grass-roots campaign, starting in Anacostia, where he lives. Gurley said affordable housing for the middle class would be an issue in his campaign.

Gurley is the fourth officially declared mayoral candidate. The others are Mattie Taylor, a former school board member and former D.C. employment services employe; Brian Moore, a Ward 2 community activist and health care consultant, and Dennis Sobin, publisher of sexually oriented materials