/usr/share/mythbuntu/plugins/ is in mythbuntu-common 0.78.2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/mythbuntu/plugins/python/
/usr/share/mythbuntu/plugins/python/mysql_configuration.py
/usr/share/mythbuntu/plugins/python/mythbuntu_repos.py
/usr/share/mythbuntu/plugins/python/plugins.py
/usr/share/mythbuntu/plugins/python/proprietary_codecs.py
/usr/share/mythbuntu/plugins/python/remote.py
/usr/share/mythbuntu/plugins/python/services.py
/usr/share/mythbuntu/plugins/python/startup_behavior.py
/usr/share/mythbuntu/plugins/python/system_roles.py
/usr/share/mythbuntu/plugins/ui/
/usr/share/mythbuntu/plugins/ui/tab_mysql_configuration.ui
/usr/share/mythbuntu/plugins/ui/tab_plugins.ui
/usr/share/mythbuntu/plugins/ui/tab_proprietary_codecs.ui
/usr/share/mythbuntu/plugins/ui/tab_remote_control.ui
/usr/share/mythbuntu/plugins/ui/tab_repos.ui
/usr/share/mythbuntu/plugins/ui/tab_services.ui
/usr/share/mythbuntu/plugins/ui/tab_startup_behavior.ui
/usr/share/mythbuntu/plugins/ui/tab_system_roles.ui