What was found
CABIN ALT CAUTION MESSAGE AT 19,000FT. RAN THROUGH CABIN ALT WARNING QRC, FOLLOWED BY CABIN ALT CAUTION QRH. MASKS DEPLOYED. FA REPORTED WISPY WHITE SMOKE IN CABIN MOST PROMINENT IN AFT PORTION ALONG WITH ELECTRICAL BURNING ODOR. PILOTS ALSO SMELLED ELECTRICAL BURNING ODOR. EMERGENCY WAS DECLARED. ON LANDING CABIN ALT WARNING HAD CLEARED, CABIN ALT CAUTION REMAINED. (FLIGHT 5022) OPS CHKD FOR THE CABIN ALT WARNING & CAUTION MSG IAW AMM 21-31-00. OPS CHKD GOOD. REF EAML 1868210, EAML 1868152, EAML 1866778, AND EAML 1868025 FOR TROUBLESHOOTING & WORK PERFORMED.