https://elise.ema.gov.sg/elise/homepage_public_menu.jsp        Provides guidance for qualifications and prerequisites for the 3  grades related to electrical installations. 
LEW must be conversant ith SINGAPORE STANDARD SS638 Code of practice for electrical installations ad the the relevant ELECTRICITY ACT(CHAPTER 89A. ELECTRICITY (ELECTRICAL INSTALLATIONS) ELECTRICAL WORKERS AND CONTRACTORS LICENSING ACT
Singapore Standard SS 650 Code of Practice for Temporary' Electrical Installations — Part 1: Construction and building sites 
Singapore Standard SS 650 Code of Practice for Temporary Electrical Installations — Part 2: Festive lighting, trade fairs, mini-fairs and exhibition sites.
Experience with electrical systems in buildings which includes supply system ie generators, UPS, fire alarm, lighting, lightning protection system  would be helpful to cover related work. Broadly speaking, electrical work is presented in drawings and specifications. Students are attracted to new technologies, IT and Ai and shun traditional engineering courses causing a lack of professionals and technicians and probably replaced by foreigners. This is a world wide senario. I had work with a M&E services contractor and the company is run by staff from malaysia, myanmar and philipines and the work site staff  by indian nationals. In fact they are very good even without local certifications.