our customers could use one of these alternative parts vs part 1866-3009-ND, of IRM-02 (2W) series from MEAN WELL USA Inc.:
RAC02-05SGA as AC/DC CONVERTER 5V 2W from Recom Power
or
PSK-S2C-5 as AC/DC CONVERTER 5V 2W from CUI Inc.
Please review the datasheets to ensure the alternative will work for your application.