I think you may be slightly confused!
With the exception of elections after leaving beta (often referred to as "graduation elections") existing moderators are never required to run in an election, only new candidates are. So, unless one of the moderators here states their intention to step down, they will remain on the roster. Additionally, there are no third-party nominations. Only the candidate can elect themselves, though y'all are welcome to encourage people you think would be great as a moderator here.
If there are no nominations by the end of the election, nothing will happen. Stack Exchange requires sites to have three moderators minimum with the intention that they are there to support the site and keep it in good shape. There are currently four people on the roster. The current moderation team asked for additional slots to help carry the load of managing this site, so we're running an election to hopefully find others interested in helping out.
I sincerely hope that they do get some help as I very much care about this site and I think the mods here are some of the best on the network (maybe some slight personal bias here...;) ). The last thing I want is for them to feel overburdened with the work here, which could lead to them deciding that they need to step down.
I know there are many great users on this site who have given a lot of time and effort to help cultivate the questions and answers asked here. I hope that we can get at least three of them to step forward to help the site.
If it helps anyone decide, while it's best if you can commit to at least six months of moderation, this isn't a permanent role unless you wish it. Moderators are free to step down at any time with no penalty. We appreciate any extra effort on the part of our communities. If anyone has any questions about moderation, please feel free to ask. Years ago I ran in an election here on ELL and was a moderator on two sites before I became a Community Manager, so I think I know a bit about what this site and moderation are like.