Firm-paid externs in chambers?

Justice Robie chairs the
Supreme Court Committee
on Judicial Ethics Opinions

Can an appellate court justice accept the services of an attorney to temporarily work in the justice's chambers when the attorney is an employee being paid by a law firm? Nope:

In an expedited opinion posted on the committee’s website, the Supreme Court Committee on Judicial Ethics Opinions (CJEO) concludes a justice may not allow a law firm attorney to work for the justice because the attorney’s services are a prohibited gift from the law firm under the Code of Judicial Ethics and could appear to lend judicial prestige to advance the law firm’s reputation.