You know times are hard when Uncle Sam has to stop printing money in order to save on his heat and light bill.

This isn't a sly dig at Reaganomics or anything like that. The honest-to-gosh truth is that the Bureau of Engraving and Printing, the fascinating factory on 14th Street that cranks out $12 million in currency every few hours, and 33 billion stamps each year, will shut its doors over the Christmas to New Year's period.

Normally, the BEP presses roll six days a week. But during the Christmas to New Year period BEP, like a lot of other government agencies, has a high rate of absenteeism. That is because people with vacation time can take four days off (Christmas falls on Friday and is a holiday) and get a 10-day vacation. This year BEP brass decided that it would be cheaper to have its 2,500 staffers stop printing money for a while rather than heat the building for a skeleton crew. It expects to save between $300,000 and $500,000 by closing the office.

Workers who have vacation time (annual leave) will be able to use it. Those who don't will be put on furlough without pay. BEP brass say the shutdown has nothing to do with budgetary problems that other agencies are facing. They first considered the shutdown earlier this year and have been negotiating with employe unions. Official announcement of the shutdown will be made around Dec. 1 so that tourists who show up hoping to see money printed, and visit BEP's fascinating gift shop, won't be disappointed.

A warning to private entrepreneurs: Despite the Reagan administration push to contract out work performed by the government, there is no plan afoot to relax Uncle Sam's monopoly on printing money no matter how little it is worth these days. And in case anybody out there is thinking about visiting the BEP stockroom during the shutdown, be advised that its alarm systems and guards will be on duty as per usual.