Lincolnshire Fire and Rescue Service is currently searching for people to take on this role.
On-call firefighters carry pagers; when these sound, they need to get to the fire station within five minutes from their home of place of work.
However, shifts can be flexible and based around other commitments and responsibilities.
Watch Commander Support Kerry Raynor, at Sleaford Fire Station, said: “We’re particularly looking for people to cover shifts from Monday to Friday during the day and occasional weekends.
“This could be the perfect role for you if you’ve got older children or work flexibly from home or from somewhere nearby.
“We’re always happy to meet people who are interested in becoming On-Call firefighters and to show them round the station, or to talk to people about what the job involves.”
Applicants must be aged 18 or over.
They will also need to provide their work or academic history for the last three years and contact details for two work referees.