Pennsylvania Folk Art Day: craft demonstrations and sale, 1-5 p.m., May Wing, Baltimore Museum of Art CHarles and 31st Streets, Baltimore Devils: 301-498-7100.

Conclusion of the Prince George's Fireman's Assn. Ladies Auxillary Home Crafts Fair, 10 a.m. - 4 p.m., West Lanham Hills Volunteer Firehouse, 8301 Goodluck Rd, Lanham. Admission.

Conclusion of the fifth annual All- Glass Show & Sale, 11 a.m.-6p.m., Alexandria No. 2 Holiday Inn, Telegraph Road Beltway exit, Alexandria, Admission. This Week

Full Circle third annual like show: exhibit and sale of 35 designs by Chinese, Japanese, That, German, English and American craftsmen, 10:30 a.m.-5:30 p.m. Monday-Saturday, Full Circle, 112, King St., Alexandria. Details: 683-4500.

Woodlawn Plantation Needlework Exhibit of first-and second-place winners and special pieces, 9:30 a.m.-4:30 p.m. MOnday through April 3, Woodlawn Plantation, Mount Vernon. Details: 780-3118.

Architectural stained glass by Sal Fiorito, metal sculpture and jewelry by Douglas Legenhausen and watercolors by James E. Fitzgerald, daily except Sunday, Visual Art Center, Long reach Village Center, Columbia, Md., through April 6. Details and hours: 596-5133.

Sully Plantation fourth annual Egguery Celebration: egg-decoration exhibit and demonstration, noon-5 p.m. Saturday and Sunday (April 3), Rte. 28, Chantilly. Admission. Details: 437-1794. Classes

Registration for Smithsonian Associate Spring Classes in antiques, architecture, bookbinding, calligraphy, city planning, design, enameled tiles, fabric dyeing, furniture-making and restoration, mobiles and stabiles, and stained glass is under way. Tuition. Details: 381-5157. Postponement

The Woodrow Wilson House Spring Booksale, originally scheduled for March 19-26, is now slated for June 11-19. Donations of books will be accepted through the end of May at Woodrow Wilson House, 2340 S. St. NW. Details: 382-6876.