This was used for door ways as a door bell and also used as other set dressing. One of the most iconic pieces from DS9. This particular design with the back panel was used in episodes like season 1 episode 17 when explosions stopped the doors from opening. they had metal tabs on the back to make them magnetic to be easily "ripped" off to use the manual override pull switch under the panel. Seen twice at the end of that episode and again in "Seige" in season 2.
