Describe the wiggling? Is it the axle in the dropouts? Make sure the wheel is straight, chain tension is right, and tighten up those nuts. If there is some play between the hubshell and the axle, that's ok, as long as there isn't too much. That little bit of "slop" is for the bearings, to make sure that they roll smoothly. You adjust this with the cone nuts on the axle. These are those really skinny black nuts on your axle that are in pairs on either side of the hub. You basically adjust these by tightening them ever so carefully until there is no play in the wheel, then back it off just to the point where you can feel some play. If these nuts are too tight, you can ruin your bearings. Too loose and you can also ruin your bearings. You don't have to be super precise with the exactness of the adjustment. Just follow the procedure listed above and it should get you to where you need to be.

Cone nuts reqiure cone wrenches. These are skinny, so that you can tighten then up one at a time, and look like they were made from thin metal plate.

Images - https://www.google.ca/search?q=cone+...IVTwiSCh0E6QMs