Mitch Snyder is sitting in the Euclid Street walk-up headquarters of the Community for Creative Non-Violence, the group that he has been leading for the past year in a death-defying, high-wire political act sans net. The phone rings. It's a radio station calling. Mitch, looking weary but no less cagey than usual, puts the reporter on hold, then hands another reporter his latest draft statement on the saga of CCNV's shelter for the homeless at 425 Second St. NW.

News organizations are but one element of the balancing act Snyder is undertaking to quash the U.S. Department of Health and Human Services' plan to replace his shelter with one in Anacostia run by a rival homeless advocacy group. The draft statement, a classic Snyder document, interposes conflicts between:

*The Navy Department and HHS.

*Anacostia and the rest of the city.

*Outgoing HHS Secretary Margaret Heckler and a subordinate.

*The D.C. Coalition for the Homeless and CCNV.

*The District government and various parties.

*The homeless and the elderly.

*Snyder and President Reagan.

In short, it is an elegantly engineered construct typical of his efforts at keeping CCNV up on the wire and not down on the floor of some circus tent. The Second Street shelter's days may be numbered, but even Snyder's enemies concede he has extended its run with a deftness worthy of the Flying Wallendas.

The latest chapter in this story centers on the federal government's Anacostia plan and Snyder's bid to discredit it. He wants to discredit it, of course, because its fulfillment would end his plan to build and run a model shelter funded with federal dollars.

Snyder's effort operates on several fronts. One, involving neighborhood organizations in Anacostia, joins CCNV and Anacostia residents in criticizing the plan as just another attempt to dump unwanted facilities on an area of the District that has been dumped on too much.

In Anacostia already, you will find one of the world's largest sludge processing stations, the only federal mental hospital in the United States and several residential facilities for drug users, delinquents, ex-prison inmates, et cetera.

Snyder has been counseling Anacostia activists on how to fight the plan and even has suggested an issue they might use to obstruct the proposed shelter, which HHS and the Coalition propose to open in a week in a Navy Department building at 1900 Anacostia Dr. SE.

That issue is the alleged misallocation of $500,000 in funds that are a part of $3.7 million offered by the federal government to the Coalition to operate the temporary Anacostia shelter and subsequent long-term ones.

Snyder says the $500,000 has been wrongfully tapped from Older Americans Act funds designated for the aging. The federal government, he says, is playing a shell game with money in order to improvise a plan that will satisfy the U.S. Court of Appeals, which has been considering the shelter question.

HHS officials say there is no problem with the allocation, since the $500,000 will be used only for homeless persons over the age of 60, as the act requires.

A spokesman for Rep. Mario Biaggi (D-N.Y.), chairman of the human services subcommittee of the House committee on aging, said that using the money for the elderly homeless appears to be "questionable" in view of the act's priorities on providing nutrition, transportation and legal services as well as helping elderly persons who suffer from Alzheimer's disease, abuse and neglect.

For Snyder, the allocation issue serves several purposes: It gives the Anacostia residents ammunition in their attack, gives the federal agencies something to fight over and suggests to the appeals court that there's something fishy going on at HHS.

With a wary Mayor Marion Barry steering clear of the fight on the basis that the shelter is a federal problem, the CCNV leader is struggling to show that federal officials are incapable of resolving that problem. As long as he can do so, he can continue the campaign he began last year with the 51-day fast that brought Reagan's promise of a model shelter.

That's a long time on a high wire, but nobody ever said Mitch Snyder doesn't like heights.