According to the FCC's Small Entity Compliance Guide for Third Party Fundraising:
NCE stations may conduct third-party fundraising only for entities that are recognized as tax exempt, non-profit organizations under Section 501(c)(3) of the Internal Revenue Code. This limitation on eligible beneficiaries will provide NCE stations and their audiences assurances that the third-party organizations that benefit from on-air fundraising are bona fide non-profit groups.
The Fraternal Order of Police is not considered a non-profit organization under §501(c)(3) of the Internal Revenue Code. It is considered a fraternal benefit organization under §501(c)(8) of the IRS Code. Labor unions would be under §501(c)(5) of the IRS Code.
Because the Commission's decision in this appears to only cover §501(c)(3) organizations, interrupting programming to raise money for the FOP or a labor union is not permitted.
Please consult with an attorney who specializes in FCC subject matter.