They can spawn all over the fucking place (in the hospital).
1: Check the ledges in both showers (Where soap is).
2: Check the seats of all chairs (Yes, they can be on just about every chair).
3: Check the cabinets in the doctor rooms.
4: Check all the beds in the infirmary.
5: Check the desks in the monitoring room.
6: Check the tables in the room where the door to the costume is.
7: They can even be in the two rooms past the costume on the chairs, before the ammo recharge room.
8: You might be able to find them on the surgery beds too, but I don't remember finding any on them.
The cutoff for where you can no longer find the remotes is the door that has an arrow on the floor in front of it. Don't go into the room with the ammo pickup.
The ones you're probably most likely to miss are the chairs or cabinets, they can be hidden extremely well. The remote can even be on the chairs in the rooms with the cabinets, if you don't walk right up to it and look over the top of it, you can miss it, same with the cabinets.