You are reading the census for your ancestor's residence and it says "in Bridgehill Farm". You notice that others on the page are "at Bridgehill Farm" You may not think anything of it. You may think in and at are one and the same. But they aren't. The ancestor in Bridgehill Farm is a tenant farmer, meaning he doesn't own the farm but works the farm and is essentially in charge of the farm for the landowner. He is a permanent resident on the farm. Those on the page listed as being at Bridgehill Farm are workers on the farm. Here's the breakdown for land ownership on a census:
of means the person is the land owner
in means the person is a tenant farmer who resides there full time
at means the person is a farm worker
You will often find that there is a "big house" on the farm where the landowner lives and a smaller house where the tenant farmer resides. Often, larger farms had a small set of row houses where the workers would reside. They may or may not have resided there full time, depending on their position. For instance, the head dairyman would be listed as being at the farm, but his job was important enough that he needed to be onsite. Milkers would not have lived on the farm.They would have a separate residence and would attend the farm each day for work. On the census, their "occupation" would be listed as farm worker.