SHOULD HOUSE subcommittee investigators looking into irregularities in the 1980 election campaign have the right to look at each and every document in the Reagan campaign files? Should they be required, as well, to examine all the Carter papers, or the Anderson papers or the Barry Commoner archives? How about Libertarian, Vegetarian, Socialist Worker and Communist Party files?

The Justice Department has already been charged with the responsibility to investigate crimes that may have been committed when information contained in Carter campaign material turned up at Reagan campaign headquarters. We still do not know whether government employees were involved, whether the information was bought, stolen or freely given or whether the material in question was from secret government documents. The FBI has 10 agents working at the Hoover Institute in California, where the Reagan campaign files have been deposited. Rep. Don Albosta, chairman of the subcommittee investigating possible government ethics violations, wants to send his men into the archives to search the files for any relevant papers the FBI might miss. Republicans counter that if this is done, the Carter campaign files should be made available to Republicans, too. Before this politically explosive and dangerous precedent is established, everyone concerned should reassess his demands.

The trustees of the papers at the Hoover Institute -- the president, Edward Meese and Michael Deaver -- have suggested in writing that a step-by-step approach be taken. Initially, they say, the Albosta subcommittee should take a look at everything the FBI agents have found and believe to be relevant. Rumors that this offer is being modified should be put to rest by the trustees. There is every reason to assume that the FBI search will be objective, thorough and nonpartisan, especially since the only politically appointed pereson in the bureau is the director, who was named by President Carter.Then, the subcommittee could consult the Hoover archivist concerning the content of the files and their organization. They could also ask the trustees for specific categories of material -- all papers relating to the debates, for example. Finally, if differences remained, negotiations on the terms and conditions of direct access to the files would be resumed.

It is in the subcommittee's interest to take the trustees' offer and begin by cooperating with the FBI and the archivist. Valuable time will be lost by prolonging negotiations and escalating this confrontation when some steps can be taken right away. The criminal investigation being conducted by the Justice Department is the main act in this drama. As to whether Democratic politicans ought to be allowed to go through Republican strategy memos, position paper drafts and memos on fund-raising techniques -- and vice versa -- some second thoughts are in order.