I recently drilled into what I thought was a stud behind the wall. It turned out to be a 3" PVC drain pipe. It is a clean 7/64" hole. A coupling will not fit within the drywall. I was thinking of filling the small hole with plumbers epoxy. Then, cutting/trimming a piece of a coupling and cleaning/gluing it over the hole with PVC cleaner/cement. A plumber told me I should put a screw with a rubber washer in the hole. This seems like a bad idea to me.
Thanks in advance for your feedback.