Yea, someone else with a wild baby mouse
... When Jimmie and I found ours, the end of Dec, she still had her eyes closed, we named her Lucky. For about the first 2 weeks I fed her human soy formula, followed the directions, then slowly started making it a little thicker for another week (I tried to keep on a schedule of every 4 hrs). The following week I started making it according to the directions again but slowly adding human baby cereal to it and gradualing putting less formula in it until it was just cereal (feeding about every 6 hrs), I was also putting solid food in her cage, like cheerios, oatmeal, and total cereal to start with, then slowly introduced other foods to her. I'm happy to say that she is happy and just as hyper as can be. Lucky for us, I guess, one of our female rats had an accidental litter about 2 weeks after we found her, so after they were weened we slowly started introducing her to them. Once we got the females seperated from the males, we kept Lucky with the girls and they got, and get, along just fine. After about a month, we slowly introduced the babies and Lucky to our first 2 females, and the mother again. Lucky has become close with one of the first ones, Greyson, they cuddle with each other all the time. I'm also glad some of the girls have stayed small, the runt of the litter isn't much bigger than Lucky, who just seems big for a mouse to me.
Anyway, sorry to ramble on like I did, I'm just so happy I rescued her and she turned out great and so friendly. So I wish you the best of luck with yours. Keep in touch as to how everything is going. Also, if you have any questions, I'll answer the best I can. And make sure you keep a small water bottle in there too.