With the deadline to return nomination papers for the town’s annual election approaching, four residents have taken out the forms to run for one seat on the Board of Selectmen. The position was left vacant when Jesse Mermell resigned in January to accept a position in the Patrick administration. The potential candidates are Andrew Ghobrial, of Ivy Street; Anthony Ishak, of Freeman Street; Roberta Ellen Pollard, of Beals Street; and Neil Wishinsky, of Henry Street. Four residents also have taken out papers to run for three seats on School Committee: Incumbents Helen Charlupski, Susan Wolf Ditkoff, and Henry Warren, and David Pollak of Lancaster Terrace. The deadline for candidates to file nomination papers, which for townwide offices must be accompanied by the signatures of at least 50 local registered voters, is March 12. The annual election is set for April 30.