Highly polite and slightly old-fashioned, common in Republican-era novels and formal letters. NEVER use 府上 for your own home — that would be like calling your house 'my mansion'. For 'my place' use 寒舍 (humble dwelling) or just 我家.
mistakes
府上 refers to either the listener's home or their hometown — context decides. 您府上是哪里? usually asks 'where are you from?' rather than 'where do you live?'