Pennsylvania Homeschoolers offers AP Courses for all homeschoolers (you do not have to be from Pennslyvania).
From their website:
We offer Advanced Placement (AP) courses to homeschooled students worldwide. (Our classes are not available to public or private brick-and-mortar school students.) Our 2018-2019 school year class descriptions are now updated and teachers are taking new applications and our online store is ready for paying tuition once you’ve been accepted. To learn more about our classes, please browse our course descriptions and the reviews from past students and their parents. Reviews are linked at the end of each course description.
Find out more at http://www.aphomeschoolers.com/index.shtml