Mid-Shore Senator Richard Colburn filed three bills that call for changes in state election law when electing a US Senator or US Congressman. One bill would require the governor to call a special election if a Senate seat becomes vacant during an elected term. Another would allow the Governor to appoint someone to the Senate to fill a vacancy only until a successor is elected in the next congressional election. The third would require a runoff if neither candidate got more than 50 percent of the vote in that special election.