My HVAC unit sits in a housing that is built into a wall that separates the indoors from the outdoors. The wall consists of some kind of material - that I suspect to be asbestos tile of some sort (the building was built in the early 1970s) - that's sandwiched in between two sheets of metal. In other words, the suspected asbestos tile was encased by the developer of the building. This allowed the asbestos tile to be completely isolated, unexposed and left undisturbed.

A hole the size of a quarter was accidentally drilled out of it recently during a home renovation project. The hole on either side of the wall was then closed off by putting in an electrical junction box that doesn't house anything - just covers the hole made.

As the homeowner, what must I do to make this unfortunate situation as safe as possible? Thank you in advance.