A man carrying a .25-caliber pistol walked up to a Connecticut Avenue NW fireworks stand last night and demanded the receipts from the busiest day of the year in the pyrotechnics trade - the eve of the Fourth of July.

The sum at issue was about $4,000, and in the words of a detective in the 2nd District, the proprietor of the stand, John Greenwell, "said 'you ain't getting it' or words to that effect."

Greenwell grabbed for the man's gun, a struggle ensued and the gun flew out of the temporary stand at 5001 Connecticut Ave. It fired once. No one was hit.

Meanwhile, police said, at least three persons came to Greenwell's aid. The stand was largely demolished by the fray, but the would-be robber was finally subdued. Robbery squad detective Renager Lee said an 18-year-old New York man was charged with attempted robbery.

In another incident last night connected to fireworks, a Southwest church was heavily damaged by a fire that the pastor's wife said may have been ignited by firecrackers thrown on to the church's roof.

The fire broke out about 7:30 p.m. at the Carron Baptist Church, 1354 First St. SW. Mrs. Leroy Waldo, the pastor's wife, said investigators told her that firecrackers ignited material in the gutters.