Drop ceiling hole patch

Another drop ceiling tile? There may be spares up there, take a flashlight and a ladder and check it out. Or, glue an old smoke detector over the blemish.

A blank power outlet or data point plate?

How large a hole/device? E.g., an octagonal box for an AP? Or, a half-tile hole for an air register? Or, wifi antenna assembly?

The obvious solution is a replacement tile -- so, I assume the "pattern" is no longer available.

You can check for spares elsewhere (often collecting dust IN the ceiling space).

In a pinch, assuming it is in a very noticeable location, swap that tile with another in a less noticeable location. If THAT is still unacceptable, consider finding a location in which you can replace MULTIPLE tiles to make a deliberately different sub-pattern. So, it looks *intentional*. E.g., a set of four tiles in the center of the room. Or, the tiles on either side of each air duct. Or, the tiles around the perimeter of the room. Or...

Or, consider adding a lighting fixture "somewhere" and stealing the tile that it replaces for use in that spot.

How about a ventilation grill? You can't have too much ventilation.

Yep. Testing a pneumatic vertical antenna mast indoors was not a great idea. I exchanged the damaged ceiling tile with one from a closet, where the jagged hole would not be noticed. If you can't fix your mistakes, you can always hide them.

Other ideas...

Steal a ceiling tile from a neighboring office and use it to replace yours. If it's the wrong size, cut out a matching hole plug and glue the plug in place.

Cap plug or rubber cork? Enlarge hole to fit. No one will complain as such things are expected from engineers.

FixAll. While it's made for plaster, a small 3 cm dia hole will probably be self supporting. Glue some fiberglass mesh drywall tape backing across the hole for support: Fill the hole with FixAll, let dry, and hope that the colors match. It's important to use FixAll or some flavor of drywall patch because they do NOT shrink.

Install a shower head and inform gawkers that its part of the fire sprinkler system. If you add a pull cord, you can tell them it's for when you're working late.

Ceiling speaker grill to hide the hole.

Ed

They make blind covers for electrical boxes.

search for "Ceiling Box Cover Plate" The plastic ones are cheap, can picked up anwhere and can be rigged up in creative ways.