Thousands of potential "cowboy" electricians are being produced as colleges and training firms cash in on the demand for short courses, industry leaders have warned.
Colleges and companies are accused of offering applicants the chance to train for a trade in a matter of weeks, instead of on longer courses leading to industry-recognised qualifications.
SummitSkills, the sector skills council for the building services engineering industry, is leading the outcry together with the Electrical Contractors' Association (ECA) and JTL, the biggest provider of apprenticeships for the sector, which also covers plumbing.
They claim the short courses on offer are leading to underqualified workers advertising themselves as skilled craftspeople.
In a statement, the three organisations said: "These training providers often charge exorbitant rates for courses that imply entry into the industry as a qualified electrician.
"More importantly, they fail to deliver what is required in terms of industry and government standards.
"Ironically, in the case of some publicly-funded institutions, government funding can be obtained to subsidise these courses, making them even more attractive."
They pointed to Home Office statistics that show that around 12,500 fires due to electrical faults are reported each year in the UK, killing or injuring more than 600 people.
They added: "It is of growing concern that a number of training providers are prepared to exploit commercial opportunities brought about by the current skills shortage in the electro-technical industry.
"The result is that employers and consumers are presented with woefully under-trained tradespeople, which could have devastating health and safety implications.
"Most people who choose this route into the industry end up working in the less-regulated end of the market and may have difficulty finding a job."
They said stories of the high salaries earned by electricians and plumbers have led to oversubscribed apprenticeship courses and "a rash" of shorter courses being offered by colleges and commercial training providers.
Denis Hird, chief executive of JTL, said: "Rogue trainers are not only giving many people the false hope the courses will lead them to be fully qualified, but are also failing to deliver what is required by the industry and government.
"An influx of underqualified and underskilled craftspeople will result in further misrepresentation of the electrical trade and the return of the cowboy."
Keith Marshall, chief executive of SummitSkills, said: "Unfortunately this problem is not exclusive to the electrical industry. There are also high numbers of fast-track plumbing courses that imply qualified plumber status upon completion.
"We cannot let either industry suffer at the hands of these rogue trainers.
It's important that steps are taken now to nip it in the bud."
Iain Macdonald, head of education and training for the ECA, said thousands are being lured into changing their jobs by advertisements offering six-week courses to "become an electrician".
But after handing over up to pound;4,000 for the training, they end up with "rafts of certificates that do not amount to an industry-recognised qualification".
Mr Macdonald added: "It takes 750 guided learning hours over a four-year period, with an on-the-job assessment, to obtain an NVQ to become qualified to industry standards. It is the only way to guarantee that people are competent and the work they do is safe.
"These courses may offer theory, but where is the on-the-job experience? Working in the pitch dark in a loft with out-of-date wiring is a lot different to doing test work in a classroom.
"Consumers are not well informed about qualifications. If someone brandishes certificates from training providers at them, how are clients to tell the difference?"