The simplest answer is to complete your application to WikiTree by volunteering to be a part of the community, then putting your grandfather's profile out on WikiTree so that we can work on connecting him to the larger part of the global tree. Once you're able to enter family information, there are many out in the G2G community who volunteer to help others build their trees, seek sources to prove connections, and build profiles in general to expand the global tree.
If you're only interested in seeking information regarding your grandfather and don't want to join the community, then we'd need specifics to see first if he's already out in WikiTree somewhere, and if not, if records exist somewhere to help answer your question.
Hope that helps.