MADISON, Wis. — About 188,000 people in Wisconsin who are registered to vote but didn't vote for the past four years will be receiving a mailing notifying them that they will be taken off the rolls unless they take action within 30 days.

The Wisconsin Elections Commission on Thursday approved sending the routine mailing, which state law requires be sent every two years.

In 2019, more than 113,000 notices were sent and about 16,000 people requested that their registration continue. That is a response rate of about 14%. In 2017, more than 381,000 notices were sent and about 28,000 requested continuation, a response rate of only about 7.5%.

The commission voted unanimously to send the mailer as required by June 15.

The mailing targets those who have not voted and is separate from another mailing that goes to voters who may have moved. What to do about those voters has been the subject of a legal fight, with the Wisconsin Supreme Court ruling earlier this month that the Elections Commission should not purge people on that list from the rolls.