Sen. John H. Chafee has become the third Rhode Island politician in danger of losing his ballot position because of a minor problem on his candidacy papers. John J. Staradumsky, an independent candidate for Chafee's seat, has filed a formal objection to Chafee's candidacy, meaning the state Board of Elections must decide whether to throw Chafee off the ballot, board Chairman Joseph R. DiStefano said Wednesday. The two-term Republican senator listed his Warwick address on his filing form as 1128 Ives Road, while his voter registration card omits the house number. State law requires the two forms to match exactly. Similar discrepancies already have jeopardized the candidacies of Republican Rep. Claudine Schneider and Democratic gubernatorial candidate Bruce G. Sundlun. Gov. Edward D. DiPrete said at the time he would call a special session of the General Assembly if necessary to get them back on the ballot. Michael Ryan, a Chafee aide, said Wednesday homes on Ives Road were not numbered when Chafee registered to vote in 1953. ``We expect common sense to prevail, hopefully in all cases, but certainly in this one,'' Ryan said. The elections board will hear Chafee's case July 26. It has scheduled a July 25 hearing on the Schneider and Sundlun cases. If the board rules against Chafee, he would hae to run a write-in campaign against Democrat Richard A. Licht in the Nov. 8 general election. Chafee is unopposed for renomination. DiStefano has refused to predict what his board will do, but said it has ruled ``time and time again'' against lesser-known candidates who made similar mistakes. ``Everybody knows what the precedents are,'' he said. ``We've indicated that quite clearly.''