Witness Sunshine Resolution - Amends Rule XXVI (Committee Procedure) of the Standing Rules of the Senate to require each Senate committee (including the Committee on Appropriations) to require each witness who is to appear before the committee to file with the clerk of the committee, at least one day before a scheduled appearance, a disclosure form identifying any arrangement, affiliation, relationship, or substantial financial interest the witness has with any organization, company, or private or government entity directly related to the subject of the hearing, unless the committee chairman and the ranking minority member determine that there is good cause for noncompliance. Allows a witness who is a federal employee to comply with this disclosure requirement, at the discretion of the committee chairman and the ranking minority member, by submitting an Executive Branch Personnel Public Financial Disclosure Report.