You'll note the deathly silence to your post DSF.
Basically because many of us would be happy to take them off your hands. And have them made into sausages. But rehoming them is another matter.
You don't say what breed they are - so I'm assuming they are big? Big pigs eat a lot of food, as mere pets or in a sanctuary, and for someone to take 4 is an incredibly big ask. They need space, they make a mess and they cost a lot to feed. Especially as feed prices have doubled in the past year.
So - if you advertise widely you
might find someone like you who has some land to clear; but even then they will ultimately be going to the butcher.
Not helpful I know. I once had a sow I was fond of and didn't want to eat. I gave her to a friend who had a smallholding. I didn't ask but I know he got her slaughtered. However at least she didn't go through a market on her own, not knowing what was happening; and that was ultimately going to happen anyway.
Similarly, I once took on a sow that someone had raised as a pet on their allotment and she was now too big. We never discussed what happened to her. I kept her for a few months so she at least had a bit of freedom and company before she went for slaughter. Again I didn't put her into market, but straight to the butcher. The sausages were lovely.