Outside Sacred Heart School, the sun shone brightly in the Mt. Pleasant neighborhood as the city enjoyed its first dry Saturday in weeks. Inside, 300 members of Washington Innercity Self Help (WISH) crammed into the school's small auditorium at 16th Street and Park Road NW for the fourth annual congress to honor the organization's faithful and elect new members.

But the gospel singing, hand-clapping and frequent "amens" punctuating the ceremony last Saturday were in keeping with the character of one of D.C.'s scrappiest grassroots organizations, one that has championed causes of the city's poor and elderly for the last three years.

WISH is a coalition of about 300 community organizations representing residents of Wards 1 and 2 in the District's north central area. With a constituency of nearly l00,000, the group has successfully mounted campaigns on such issues as condominium conversion, slum landlords, rent control and Medicare services.

The group boasts accomplishments that include preventing more than 650 illegal evictions in the city, halting l2 illegal condominium conversion attempts and securing rebates of more than $350,000 to tenants from illegal rent increases. WISH also publishes a D.C. Tenants' Survival Guide.

"The bad situations are better and the better situations are the best we could make them with what we have," said the Rev. Mamie A. Williams in her final address as WISH president.

This year WISH's most ambitious undertaking will be the administration of $2 million in funds from the Aetna Life Insurance Company to provide mortgage money for the purchase of homes in the city's depressed areas.

"This is a first for Washington," said Miguel Vasquez, project director. "Since the riots, no mortgage funds have come from the private sector for purchasing and revitalizing property in Wards 1 and 2."

Continuing the day's celebration of WISH victories, keynote speaker Paul Berry of WJLA-TV praised the group's activities and called for more unity among city residents.

Berry said that housing problems are so severe for the District's poor and elderly that if a resident with an infant applied for emergency housing, the child would be six years old before it was available. A senior citizen who applied for public housing today would have his name placed on a waiting list of more than 25,000, he said.

He acknowledged that his consumer reports on television help people, but emphasized the importance of groups like WISH. "I'm not the person to depend on," he shouted. "This system, this town belongs to you. Learn how to manipulate it."

While gospel renditions by the Children of Joy Choir kept the audience entertained, balloting was conducted for the election of officers.

The Rev. John P. Carter was elected president. The former pastor of Mt. Vernon Church is a veteran WISH leader.

City Council Chairman David A. Clark, who dropped by briefly, took advantage of the lull during ballot counting to remind the group that the city's present condominium conversion law will expire in September.

"A lot of hope exists that tenants of this community are disorganized," he warned. "You must show them they are wrong."