/usr/share/blt2.5/demos/scripts/ is in blt-demo 2.5.3+dfsg-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/blt2.5/demos/scripts/barchart2.tcl
/usr/share/blt2.5/demos/scripts/bgtest.tcl
/usr/share/blt2.5/demos/scripts/clone.tcl
/usr/share/blt2.5/demos/scripts/demo.tcl
/usr/share/blt2.5/demos/scripts/globe.tcl
/usr/share/blt2.5/demos/scripts/graph1.tcl
/usr/share/blt2.5/demos/scripts/graph2.tcl
/usr/share/blt2.5/demos/scripts/graph3.tcl
/usr/share/blt2.5/demos/scripts/graph5.tcl
/usr/share/blt2.5/demos/scripts/graph8.tcl
/usr/share/blt2.5/demos/scripts/page.tcl
/usr/share/blt2.5/demos/scripts/patterns.tcl
/usr/share/blt2.5/demos/scripts/ps.tcl
/usr/share/blt2.5/demos/scripts/send.tcl
/usr/share/blt2.5/demos/scripts/stipples.tcl
/usr/share/blt2.5/demos/scripts/xcolors.tcl