My first job as a junior programmer involved running the backup each night. Once a week, I would clean the tape drive using alcohol and Q-Tips. While cleaning the drive, I would place the open bottle of alcohol on top of the drive that had a grate to allow air to flow through the drive. Yep, you can see it coming. I reached up without looking to get the bottle of alcohol and knocked it over, spilling about a quarter of the bottle before I grabbed the bottle and backed away from the drive. I stood there for a moment, waiting for the sparks to start flying, thinking about calling my boss. Nothing happened, the drive just kept going. The heat from the drive evaporated the alcohol almost immediately as it hit the internal parts. I finished the backup without incident and I decided not to tell my boss, who never found out.