I fixed a shower grout problem this week. I has a combination chandalear/fountain. I don't like water leaking out of the ceiling! I also hear what sounds like water leaking out of the drain pipe onto the ceiling but cannot know for sure without ripping the textured plaster ceiling up. The shower is above the foyer just past the ceiling for the stairs. I could rip a hole just above the bottom of the stairs for inspection without destroying the plaster work.
The question I am getting to "Is there a device that plummers or home repair experts have that allows for inspection behind the wall without making a gaping hole?" Maybe some sort of fiber optic device that with a 1 inch hole allows for inspection?
If there is a leak, I don't want to find out the hard (EXPENSIVE) way.