Soap Dish wall retailer mount Porcelain Vintage

We have a Soap Dish wall mount Porcelain Vintage/Antique item. It is a white porcelain It has age crackles all over the porcelain, some darker than others. It measures about 5" in W x about 1/2" in D x about 2 1/2" in H on the back and about 1 3/8" on other places around the dish. It has a rectangular spot on the back which I believe may have fit over a bracket?. There is some chipping around this rectangular space (it measures about 7/8" x about 2 1/8" in the opening). As described above it has an antique patina, no chips or retailer cracks just the crackling. It is fairly heavy.