NBC pulled tonight's scheduled rerun of "Night Court" late yesterday to air an episode called "An Old Flame," which showcased series costar Selma Diamond, who died earlier this week of lung cancer . . .

Series costar Harry Anderson will open tonight's program with the taped words: "This is an encore presentation of a 'Night Court' episode featuring the remarkable talents of Miss Selma Diamond. We'll miss you, Selma." . . .

Herve Villechaize, who played Tattoo on ABC's "Fantasy Island" for six years, was arrested at a Burbank hospital early yesterday morning for carrying a stolen, concealed handgun, which police found in his purse . . .

Police were called to St. Joseph Medical Center by hospital employes who said the actor was "creating a disturbance" in the emergency room . . .

Police Sgt. Tom Hoefel said that "he went to the hospital and he appeared a little intoxicated. He wanted to be admitted for an unknown reason" . . .

In the past, Villechaize has been treated there for stomach problems . . .

Hoefel said officers who arrived shortly before 3 a.m. asked Villechaize for identification and when the actor opened his leather handbag, the officers spotted the weapon, the serial number of which was traced. It was determined the gun was stolen in Georgia in 1983 . . .

The 3-foot-11 actor was booked on charges of carrying a concealed weapon and suspicion of receiving stolen property. Six hours after his jailing, a bondsman posted $1,000 for his release. He faces arraignment in about two weeks . . .

Tattoo, who was dropped from "Fantasy Island" in 1983 when he asked for a big salary raise, has been involved in two previous disputes involving guns. In 1982, his then-wife filed a civil suit -- later dropped -- accusing him of firing a gun at her. In 1983 at his Shadow Hills ranch, Villechaize called police after firing shots to frighten off a combative friend. The actor's pistol was confiscated at the time . . . Also in the News

Channel 66 was hoping to be on the air by last night after a blackout that began Sunday when lightning struck power lines feeding the WTKK transmitter, frying some of the equipment . . .

Out in San Francisco this week, the public broadcasting establishment is having its big annual get-together among representatives of the PBS stations, the National Association of Public Television Stations and the Corporation for Public Broadcasting board . . .

Yesterday, a lot of them were buzzing in the lobby of the St. Francis over action taken by the CPB board on what was presumably a routine bit of business on its agenda . . . approval of CPB support for a "trade mission" of public broadcasters to the Soviet Union this fall . . .

For some time, the CPB's Office of International Activities has helped public broadcasters put together "trade missions" to a variety of countries during which they sometimes buy products from the foreign market for airing on U.S. stations and sometimes even manage to sell U.S.-produced programs to similar systems abroad . . .

In addition to underwriting two-thirds of the annual cost of the office, CPB has contributed grants of up to $1,500 to each member of the trade missions to help defray his or her costs on such trips, and passes on full travel expenses from foundation grants made available to CPB . . .

In recent years, these trade missions have visited Peking (twice), Sydney, Tokyo and various European capitals . . .

Yesterday, a routine proposal to have the CPB office facilitate a planned September mission to Moscow (already cleared with the U.S. Embassy there), suddenly blew up into what one Democratic participant called a "full ideological war," led by CPB board chairman -- and Reagan appointee -- Sonia Landau . . .

When the charges and counter-charges had cleared, the board had voted 6-to-4 to approve a resolution which read: "Resolved that the Corporation for Public Broadcasting withdraw from its role in public broadcasting's trade delegation to the U.S.S.R. in September 1985" . . .

Public broadcasters with long memories chose to recall Nixon administration attempts -- sometimes successful -- to inject politics into CPB board activities and yesterday's action over what most considered a routine transaction had them blaming Landau for injecting her "conservative" views into CPB affairs . . .

In a telephone conversation yesterday, Landau discounted such criticisms. Some public broadcasters, she said, "have been antsy ever since I got on the board three years ago. Some people in public broadcasting are always upset." . . .

Landau said she had questioned the "idea of CPB negotiating with government organizations. We are a government organization, and Soviet TV is a government organization. We at CPB are using taxpayers' dollars and I believe that Congress wants us to concentrate on what's going on in public television here in the U.S. I'm not trying to keep the Bolshoi off public TV. Maybe PBS ought to be dealing with the Soviets. I'd have no trouble with that." . . .

Landau said that Democrat members of the board contend that "we're a private corporation and that somehow when federal money gets to us it somehow magically changes into something else. I don't happen to believe that." . . .

She also hinted that the board may be taking a further look at the status of the Office of International Activities . . .

One source close to the vote yesterday said that during the board's arguments over the resolution, "some of the Republican Reagan appointees were suggesting that the trade mission would just be dupes. As if these station managers would just go over there and buy Soviet propaganda which they would show on public TV here and the poor dumb American public would fall for it . . .

"That's silly. It's just another trip. CPB has no involvement in these trips whatever. A variety of public broadcasters try to sell and buy programs, that's all. And now they raise that old commie bogyman idea" . . .

CPB was created by Congress in 1967 as a nonpolitical halfway house to distribute federal funds to public radio and TV stations . . .

Several key participants in the fracas, including David Stewart, head of the CPB office, would not return phone calls yesterday . . . The CBS Sick List

This morning includes "60 Minutes' " Diane Sawyer, who may have to skip next week's CBS affiliates meeting in San Francisco because of what a spokesman yesterday called "a touch of the mildest kind of hepatitis." . . .

And Jon Katz, executive producer of "CBS Morning News," has taken about 10 days off so he can clear up a persistent lung infection. "He's at home and goes to the hospital every day for antibiotics," said the spokesman . . .

Not on the sick list is "CBS Evening News" anchor Dan Rather, who will broadcast from San Francisco on Monday, Tuesday and Wednesday of next week and then take it on up to Seattle, where CBS is dedicating its newest bureau on Thursday and Friday with a lot of hoopla (but no booze -- KIRO, the CBS affiliate in Seattle that is handling everything is Very Mormon) . . .

Incidentally, among the CBS Newsies going out to S.F. to entertain the affiliates will be Mike Wallace, Charlie Rose, Phyllis George and Bill Kurtis and Andy Lack, who's putting together the new prime-time magazine show "West 57th" . . .