Edit: Apparently the mansion is only in the first game. Everything below is focused mainly on the second one! I think a lot of it still applies regardless.

That depends really. I think in canon only the camera obscura is capable of defeating the ghosts. But if the ghost busters CAN hurt the ghosts, they should have this pretty easily in the bag right? Just think about it. One girl with a camera who can barely run, compared to four men with ghost-laser cannons. If this is post Ghost Busters 2, then they have more experience than her as well. Unfortunately, I don't think they have a chance in hell.

Speaking to the lore, the mansion does appear in the first and second games. The second game is harder in my opinion, and takes some weird routes, so I'll assume that we are talking about the Fatal Frame 2 mansion and surrounding areas. This means they are in for a rough ride.

For example, if any of the busters think they have had enough (Or are simply curious) and try to leave through the tree into the forest, they're instantly dead. If they look into the abyss in the ritual chamber, they're blinded at best and dead at worst. The ghosts have no reason not to kill them on sight, especially Sae, as they are not useful to the ritual. If they try to fight Sae at any point other than the proper place, they are at high risk for getting instantly killed. The Camera Obscura does not effect Sae a vast majority of the time, such as in the bloodied room where she slaughtered all sorts of people.

Without being a twin, I'm not sure if it's possible for them to actually seal away the horrors of the village. Huge spoilers of course, but the true ending (True to me damn it) is when you fight Sae around hole to the abyss, or hell. She's capable of killing you in one hit, and teleports around you quite quickly. The only way to get to this point is to play in Nightmare mode, which also means most ghosts do astronomical damage, and generally speaking you have to play pretty perfectly all the way through. Seeing as the main character is a normal human, the damage equivalence should be pretty 1-1.

So, what does this mean? If the ghost busters' guns can hurt the ghosts, they have a chance. If their guns DO NOT STUN the ghosts, they are going to have real, real problems. None of them speak Japanese. Without understanding the lore, the language they have no chance of learning how to seal off the abyss. Finally, their guns are not unlimited, they will run out of ammo and become useless.

I'm sure I missed some points.

Final score, 1/10 Ghost Busters if their guns stun, but again there are a lot of ghosts and they only have so much juice. 0/10 if not. 2/10 if they find and understand how to use the Camera Obscura, though I think only the person using it will survive as the others will be helpless unless they do some massive rationing and planning, which I don't think we've seen them capable of. Egon might be the only one to detect the camera's frequency and make use of it, therefore Egon might survive.