Legislating in the dark has often characterized hasty governmental reform efforts - especially those designed to satisfy some perceived public demand that something be done.

When the House votes today on whether to limit some forms of outside earned income for its members, the chamber will be pitch black in terms of knowing just what the real effect will be.

How many members have earned outside income? What are the sources - and what real or potential conflicts of interest are involved? How many members need the extra money in order to stay in Congress?

The drafters and supporters of the limitation rule don't know the answers to any of those questions. Up to now there has been no requirement for a member to make a detailed report on his outside income. And the legislators didn't find out the answers before writing their new rules.

How many members who do earn additional money get it from family businesses or farms? Again the drafters don't know. Yet they wrote a loophole in their rule to allow these members, whoever they are, to continue taking fees or salaries from such sources without any limitation.

if a members writes a book and it becomes a bestseller and the royalties go above the limit, will he have broken the rule and be subject to criminal penalties? If a congressman/lawyer takes a contingent fee case and gets a bigger settlement for his client and a bigger fee than planned for himself, does he give it back? Can a member arrange it so he received income after he leaves office?

The questions on the rules will be many and the opportunity for news stories endless. One top House aide involved in the reform process told the rule drafters their proposal would create more litigation than it was worth.

What conflicts have turned up in the past few years to require the outside earned income limitation? Did the Korean money go as fees to members' law firms? Did former Rep. Wayne Hays (D-Ohio) get in trouble because of his extracurricular income?

In the old days, reformers believed that public disclosure was the best disinfectant for preventing corruption and exposing potential conflicts of interest. What is wrong with disclosure here - at least a two-or four-year trail period to find out who is earning what?

The purpose of putting a limit on earned income - whether it is $8,600 or $15,000 depending on today's vote - was, in the words of Rep. Lee Hamilton (D-Ind.), a chief proponent, "to eliminate avoidable conflicts of interest in a reasonable and effective way."

Recently I wrote an article in this newspaper suggesting an outside income ban once congressional pay had been increased. It was a suggestion based on what seemed to be right, without regard to the facts.

Since then I have learned about a few cases of congressmen with outside income. One of them was Rep. Michael Harrington (D-Mass.). A lawyer, Harrington for seven years has received between $25,000 and $30,000 annually from a firm he helped organize. He conscienciously reported publicly on that income so that his constituents and his political opponents knew about it.

Last year Harrington's opponent made an issue of it in the election. Harrington was re-elected but his year, with the new pay raise for members, he has decided he can afford to sever his past connection. And besides, he doesn't want to face the political problems it caused him again.

That is the "reasonable and effective way" to get the result Rep. Hamilton and his reform colleagues want to achieve. So long as there is full disclosure, let the voters do the job, not the government through arbitrary and often inequitable rules and laws.