Pottery Shaving Mug

I am going to be really embarrassed, if this turns out to be a just a mug. Years ago, I bought this at an estate sale because I thought it looked like my father's old shaving mug. If I am wrong, please tell me and I will change this listing. It is 3 1/2 inches in height. The bottom has no manufacturing information. No chips, cracks, breaks or rough rims, but does have finish wear. Close-up condition photos by email. I need your zip code to calculate the postage.