Hannah Wexler wants me to urge parents to discourage their children from going on trick-or-treating forays this Halloween. Your reaction to her position may be influenced by the neighborhood in which you live.

"In this day and age," Hannah points out, "it is not safe for people to open their doors to strangers at night." The alternative isn't pleasant, either. Some trick-or-treaters engage in acts of vandalism when there is no response at the door.

It should also be noted that some householders are old, infirm, or even bedridden. It is difficult for them to answer the door, day or night.

On the other hand, consider the vast change that has come over Halloween and the practice of trick-or-treating during the past 30 or 40 years.

When I first began to write this column, many trick-or-treaters were teen-agers. It was they who were responsible for most of the vandalism.

The little children who dressed up as goblins were almost always accompanied by at least one parent. They were simply too small (and too innocent) to soap windows or upset garbage cans.

This column was among the first in the nation to suggest that parties be organized for adolescents to get them off the streets, and that the small fry ask for donations for UNICEF instead of begging treats for themselves. In a few short decades, vandalism diminished dramatically and millions of dollars were raised for emergency relief for children all over the world. Today, for example, only UNICEF and the Red Cross are permitted to enter Cambodia to bring in supplies for the refugees there.

In most neighborhoods, the modern approach to Halloween is a big success. The young adults have more fun dancing and socializing with each other than they ever had in upsetting garbage cans, and the little ones get their first lesson in sharing and supporting a worthy charitable activity.

The only problem along our quiet street is that all the little hobgoblins who used to ring our doorbell have now grown up, married, and begun raising little hobgoblins of their own in distant neighborhoods. So few children come to collect that we must send a check directly to UNICEF Information Service, 110 Maryland Ave. NE, Washington, D.C. 20002.

Personally, I rather miss the small fry on Halloween, but I must confess that we exercise due care before we open the door at night. The outdoor floodlights are turned on first, and we make sure just what kinds of demons are lurking out there before we open up.

But isn't it a sad commentary on our times that little children can't come calling on behalf of those who are starving without causing concern and even fear among householders?

Just a few days ago, a District Liner was shot dead when he opened the door to his home, and I'm sure the recollection of that incident will be in many minds when doorbells ring this Wednesday night. NOT GUILTY, YOUR HONOR

Mistakes in this column are almost always my fault, but one last week was not. A reference in Wednesday's column to a party for cab drivers ("tomorrow -- Friday only") was written for use on Thursday, not Wednesday. But the electronic gremlins that now inhabit newspaper plants put that item into Wednesday's column instead of Thursday's, causing a good deal of confusion. I apologize and hope that after Halloween these newspaper gremlins will join all the others in hibernation for another year. OLD HOME WEEK

Although I had vowed to make my break with broadcasting permanent, I couldn't say no when Bill Mayhugh of WMAL asked me to be on his new Friday night program (midnight to 2 a.m.) from Larry & Eddie's Restaurant.

Mayhugh has done so much for Children's Hospital, Heroes Inc., and a score of other good causes that I had to break my vow. Besides, the other two guests were to be my old friends Morrie Siegel of The Washington Star and Larry Krebs, WMAL's roving reporter, and I don't get to see them very often.

While we were on the air, who should walk in but Bob Wolff, who used to be the voice of the Washington Senators on TV, and of course Mayhugh insisted that he join us. By Sunday, about 20 people had asked me, "What's Bob doing now?" I didn't know that many people remembered the Senators, let alone Bob Wolff.

Bob was in town to telecast the Horse Show on a nationwide cable-TV network. He's headquartered in New York, does Madison Square Garden events on TV, much cable-TV work, and he also teaches courses in communications to college students. You can address him as Prof. Wolff now, but he still wants to know, "When is Washington going to get back into the big leagues?" He looks fit enough to qualify for an expansion draft.