The Board of Selectmen is inviting members of the community to a retirement party for Town Administrator Robert Mercier on March 22. The event is scheduled for 5 to 8 p.m. at the Café Escadrile, 26 Cambridge St. Mercier announced in October that he is retiring at the end of May. He has been Burlington’s town administrator since 1999 after previously holding the position from 1980 to 1986. Tickets to the retirement party are $35 (plus cash bar) and can be purchased at the town accountant’s office in Town Hall. Meanwhile, 22 people have submitted applications to replace Mercier. A consultant, the Edward J. Collins Center for Public Management at University of Massachusetts Boston, screened the applications and forwarded the names of 12 to a seven-member search committee, according to Joanne Faust, the town’s human resources director.