If the tooth has just become a little loose then the loose tooth will usually tighten back up on it's own within a week or a month.
If the tooth is too loose then it can require dental work to fix the loose tooth because a tooth that is severely loose will usually not tighten back up on it's own without having a dentist fix it.
Some teeth will naturally be loose though and there's nothing to worry about if your tooth is just a little bit loose and wiggly.
I have a tooth that wiggles slightly when I touch my tongue to it and the dentist said it was normal and my teeth are healthy.
If you have a tooth infection or gum infection that makes the tooth loose or makes the tooth about to fall out then you need dental work to fix the tooth infection or gum infection before it gets worse.