How long does a wild rat have to be dead before there is no fear of rabies from mishandling the body

Please, if you do not know the answer, don't bother answering. It won't be useful. Thanks.

If there's any moisture in the body, there's the chance yet.

The virus is in the blood and saliva, any fluids would contain it till there are no more fluids left. A mummified rat with the virus would not spread it. The virus in that rat would have died out.

I would contend it is never 'safe' to handle any remains. Safe here meaning completely free of pathogenic organisms of any kind. Bacteria and viruses are microscopic and can therefore harbour in the tiniest of spaces. So even naked skeletal remains potentially contain a buffet of microorganisms. So if you ask this with an eye to handling one, wear gloves, wash your hands etc., be careful !

It wont transmit to you unless it bites you or you eat it.