The Frick Art Reference Library has a variety of paid internships for Summer 2023:
Administration (undergraduate/graduate): https://www.frick.org/careers/library_adminstration_internship_summer_2023
Access (graduate): https://www.frick.org/careers/access_internship_summer_2023
Archives (graduate): https://www.frick.org/careers/archives_internship_summer_2023
Content (graduate): https://www.frick.org/careers/content_cluster_internship_graduate_summer_2023