Sounds like something is shorting out. If it smells "electrical" then something is cooking. I'd change the switch if you're handy (don't forget to shut the breaker off!) or get an electrician in if you're not.
Here's some good guidlines for working on your own 'lectricity and in your case I'd pay special attention to #8
Technicians Ten Commandments
1. Beware the lightning that lurketh in the undischarged capacitor, lest it cause thee to bounce upon thy buttocks in a most untechnicianlike manner.
2. Cause thou the switch that supplieth large amounts of juice to be opened and thusly tagged, that thy days in this earthly vale of tears be long.
3. Prove to thyself that all circuits that radiateth and upon which thou worketh are grounded and thusly tagged, lest they lift thee to radio frequency potential and cause thee to make as a radiator too.
4. Tarry not amoungst those fools that engageth in intentional shocks for they are surely non-believers and are not long for this world.
5. Take care that thou useth the proper method when thou takest the measure of a high voltage lest thou incinerate both thyself and thy meter, for verily, though thee hast no account number and can easily be surveyed, the meter doth have one, and as a consequence, bringeth much woe unto the supply department.
6. Take care thou tampereth not with the safety devices and interlocks, for this incurreth the wrath of the supervisor and bringeth the fury of the safety inspector upon they head and shoulders.
7. Work thou not on energized equipment, for as thou doest, surely will thy fellow workers buy beer for thy widow and console her in other ways.
8. Service thou no equipment alone, for electrical cooking is a slothful process and thou might sizzle in thine own fat upon a hot circuit until thy maker sees fit to end thy misery.
9. Trifle thou not with radioactive tubes and substances lest thou commence to glow in the dark like a lightning bug and thy wife have no further use for thee except thy wages.
10. Thou shalt not make unauthorized modifications to equipment, but causeth thou to be recorded all field changes and authorized modifications made by thee, lest thy successor tear his hair and go slowly mad in his attempt to decide what manner of creature hath made a nest in such equipment.
- Jack D.
New tasteless sig coming soon!