The government has restricted travel in and out of Nairobi except for cargo trucks to curb the spread of coronavirus.
Health workers are among essential service providers allowed to travel out of the capital and to operate past curfew hours.
Neighbours alerted police of the nurse’s presence, local broadcaster Citizen TV reports.
Police visited the house in the company of health officials who said the nurse’s temperature was higher than normal and took her for two-week mandatory quarantine.
The nurse reportedly identified herself to police manning roadblocks and told them she was going to offer essential services.