I know this is off topic, but this kind of repair is totally outside my experience.
I woke up one morning to find my ceramic soap holder, the kind that is usually affixed to the wall of my shower, on the shower floor. It had fallen off during the night.
It looks like it was attached with construction adhesive to the underlying plaster and lath, and then carelessly grouted just at the top. At the sides there was a good 1/4" gap. (I imagine water got between the holder and the adhesive and weakened the bond somehow.)
So what do I use to reattach it? I’ve heard both thinset and construction adhesive.
And what do I use to seal around the edge of the holder? As I said, the gap is fairly big. Do I use silicone or grout?