In 2011 with the Lions, Wright started 16 games and had four interceptions.
He will join a crowded secondary and crop of cornerbacks, including Carlos Rogers, Tarell Brown, Chris Culliver and Nnamdi Asomugha.
"We are pleased to add Eric to our team," said 49ers general manager Trent Baalke. "As an organization, we have done our due diligence and anticipate Eric working hard to contribute to the 49ers."
Around the league
Packers • Green Bay signed safety Morgan Burnett to a contract extension. Terms of the deal weren't disclosed. Burnett, a third-round pick from Georgia Tech in 2010, has started all 36 games in which he has appeared in three seasons with the team. He has 259 tackles, 28 passes defensed, six interceptions, four forced fumbles, three fumble recoveries and three sacks.
Browns • Cleveland signed rookie cornerback Leon McFadden and troubled defensive lineman Armonty Bryant to four-year contracts. McFadden, a third-round pick from San Diego State, is expected to compete for the starting job opposite mainstay Joe Haden. Bryant was arrested on drunken-driving charges shortly after he was drafted out of East Central (Okla.) University. Bryant also was arrested on a felony drug charge while in school. The only Cleveland rookie not under contract is linebacker Barkevious Mingo, the sixth overall pick.