Want to learn about chess? Sailing? Rape prevention? Real estate? Finance? Sex? Buying a car? You name it, and Alex Fraser, the last word in underground adult education, probably teaches it.

The Open University of Washington does not endow its professors with chairs - hence they must provide their own: Fraser's is an extremely tall, extremely precarious-looking director's chair that stands in the entrance to his living room and allows him to look down - professorially - on his class while scrutinizing the credentials of late arrivals. (He teaches in his living room because classrooms are another facility not provided by Open U.)

Fraser's courses, which typically meet once and for just two hours or so, are very highly concertrated. But that fits in with his theory that "in every field there are rules of thumb, aphorisms, little pieces of knowledge that can form the basis of not getting killed when you enter the field."

For instance, as he informs his class in "Money and the Young Professionals," the problems with investing in diamonds is that you will probably wind up an amateur buying from, and selling to professionals. In real estate, he says, you can become a professional - even if it means specializing in properties on a single block - and then you can enjoy the luxury of preying on amateurs.

In his "Sleep Clinic," Fraser tells his students that "just resting provides somewhere between 60 and 85 percent as much benefit as does sleeping. The thing that kills people who are worried about insomnia is that they fret about it."

In "How to Buy a House," he recommends: "You shouldn't buy the best house on the block . . . Buy a sound house - as big a house as you can afford - in an improving location for as little down as you can arrange for as long a term as you can get." If you have money to invest, and don't own a house, buy a house Regardless of whether you need one, says Fraser. You might make an equally good investment in something else, "but the amount you can borrow will be considerably less."

If you happen to have no extra money lying around, you might want to study "How to Communicate With the Opposite Sex," a course in which you can learn that "some 35 percent of rapes are committed by men on dates." This brings Fraser around to the question of "When does 'no' mean 'yes'? And how can you be sure?"

Just where does a man with such a massive fund of information on such a sweeping range of issues come from? Uh-huh. You guessed it. California.

Alex Fraser may have been born in Indiana, where his father ran a small summer resort, but at heart, like the Open University itself, he is a West Coast product. He came to Washington from Southern California 19 years ago, and the blue Pacific still seems to flow vigorously in his veins.

In his 20s, which were the 1950s, Fraser worked as night auditor and assistant manager of a hotel in Palm Springs, booked cabin reservations on Santa Catalina Island, and was "probably the only 135-pound bouncer in Texas." Then he acquired a master's degree in business administration from UCLA, went into real estate, got divorced, and came East.

Soon after his arrival here, he established the Formerly Married Society, which turned a profit of about $10,000 a year, says Fraser, but "took all my psychic energy." So he sold it. He later wrote and published a pocket-sized book, "Singles Guide to Washington," which according to Fraser, sold 4,500 copies.

In 1975 he founded, and almost immediately unloaded, Open U. He had read about a similar operation, called Heliotrope, in San Francisco, so he rounded up a faculty and began compiling a catalogue. But then he started to worry that the venture would be too time-consuming. And, unable to get liability insurance, he worried about the possibility that a student might suffer some sort of accident, sue the university, win a judgment, and reduce Fraser's business empire to shambles.

To ease these fears, he sold Open U. to Sandra L. Bremer for the $1,300 he had put into promotional and legal expenses. Bremer has been the president and all-around honcho ever since.

Although Fraser looms pretty large in the Open University catalogue, he says teaching is only a parttime activity. He earns about $5,000 a year from his Open U. work - -It paid for a quarter of my Mercedes," he says.

His main line is investing, and his main investment right now is oil - in Pennsylvania. "I have got a very nice guy, very competent, doing the pumping, doing the drilling for me up there," he says. "When you buy Quaker State or Pennzoil you are using some of my oil."

No surprisingly, the teacher of "Rape Prevention" (the one course for which he charges no fee). "Chess for Beginners," "Basic Sailing," "How to Build a Friendly Fire", "Dating, Mating and Relating", and "Luck - And You., suffers from no detectable shortage of ego. He describes his "Sexual Seminar About Men - for Men Only" as "a kind of inner intercourse . . . I attempt to tell guys how they can prolong the pleasure, I guess. I first called it 'Mini, Maxi- and Multi-Orgasms,' but we had a lot of kidding about that."

"I had one friend tell me that I had improved his love life 1,000 percent," he adds proudly. Fraser now teaches a modified version of the course called "Sexual Seminar About Men - for Women Only."

But finance is his specialty, and it is a field that lends itself more readily than sex to simple maxims.

"Leverage is the name of the game, especially when inflaiton is rampant." Fraser counsels. "This in a nutshell is what leverage is about - using OPM, Other People's Money!"

Here a troubled hand is raised. "Are you a Depression baby?" asks a student of middle years.

"Post-Depression," says Fraser, adding that, even so, he had to overcome some initial discomfort about speculating with borrowed money. New times demand new tools, he concluded.

But "you should never go into a venture without imagining what the worst thing that could happen would be," Fraser cautions. "If it's a ski resort, are there at least enough trees on the property that you could sell them and pay the interest."

"If you do take a bath on an investment, I suggest strongly that you don't continue to follow its fortunes in the new paper. It's such a temptations. It's sort of like breaking up with a lover - if you keep driving by her house, playing the same songs you played with her, going to the same bar you went to with her, you'll never forget."