What was found
CABIN SMOKE - UPON LANDING WE BOTH SMELLED SMOKE THOUGHT IT MIGHT BE EXTERNAL. HOWEVER THE SMELL CONTINUED TO GET STRONGER. AS WE EXITED THE RUNWAY I NOTICED SMOKE IN THE COCKPIT AND IN THE CABIN AND WE SHUT IT DOWN ON THE TAXIWAY AND EVACUATED THE AIRCRAFT. THE SMOKE WAS A WOOD OR PAPER SMELL. THE APU WAS RUNNING THE BLEEDS HAD NOT BEEN TRANSFERRED TO THE APU WHEN THE WE FIRST NOTICED THE SMOKE. (CORRECTIVE ACTION) REMOVED AND REPLACED AIR CYCLE MACHINE WITH A REPAIRED AIR CYCLE MACHINE IAW CL350 AMM. 21-52-13-712-801 AND 21-52-13-400-801. PERFORMED A SATISFACTORY OPERATIONAL TEST OF THE AIR CYCLE MACHINE IAW CL350 AMM 21-52-00-710-801. PERFORMED A SATISFACTORY LEAK TEST OF THE AIR CYCLE MACHINE IAW CL350 AMM 36-11-00-790-801.