If you're able to find out who the imposters are and convince the rest of the crew, they are often ejected into House (or into an active volcano!), but if you vote off the wrong players, you can expect to shortly end up outmatched. You can do the usual stuff https://www.google.tl/maps/d/viewer?mid=11kTWxy7kGpvqmtjI591jAYcy3NnqYtE