/usr/share/nagios-plugins/ is in nagios-plugins-basic 1.5-3ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/nagios-plugins/templates-basic/
/usr/share/nagios-plugins/templates-basic/apt.cfg
/usr/share/nagios-plugins/templates-basic/dhcp.cfg
/usr/share/nagios-plugins/templates-basic/disk.cfg
/usr/share/nagios-plugins/templates-basic/dummy.cfg
/usr/share/nagios-plugins/templates-basic/ftp.cfg
/usr/share/nagios-plugins/templates-basic/http.cfg
/usr/share/nagios-plugins/templates-basic/load.cfg
/usr/share/nagios-plugins/templates-basic/mail.cfg
/usr/share/nagios-plugins/templates-basic/news.cfg
/usr/share/nagios-plugins/templates-basic/ntp.cfg
/usr/share/nagios-plugins/templates-basic/ping.cfg
/usr/share/nagios-plugins/templates-basic/procs.cfg
/usr/share/nagios-plugins/templates-basic/real.cfg
/usr/share/nagios-plugins/templates-basic/ssh.cfg
/usr/share/nagios-plugins/templates-basic/tcp_udp.cfg
/usr/share/nagios-plugins/templates-basic/telnet.cfg
/usr/share/nagios-plugins/templates-basic/users.cfg