Work is hard to come by in El Salvador and for many years its greatest export has been people. They emigrate to Guatemala or Honduras and some even further. It is estimated that one quarter of the population now live outside the country, mainly in the United States. At the moment there is a coffee blight that is devastating coffee plants all over the region, forcing many rural workers off the land in search of employment. The chances of finding legal paid work are slim. It may be possible to work for some foreign owned companies or businesses, but that is uncertain.
The voluntary sector in El Salvador is well established and there are many organizations that will welcome casual volunteers wishing to contribute their efforts for free. USAID may be a chance for employment, but that depends on their needs and your skills. The best way to find work is to teach English or another language. Schools, colleges and private language institutes all require native speakers. In many places that is the only qualification that they ask. Most people can learn to teach on the job without any formal training. Some schools offer full immersion studies in English and teachers of any subject with a bachelor’s degree can apply.
Another alternative is the growing number of call centers in the country. If you can speak reasonable Spanish, enough to get you into an interview and good English, then many of these will be willing to employ you as there is usually a high turnover of staff.