Southport man jailed after setting fire to his girlfriends home
Merseyside Police said Stephen Buckley started the blaze close to a "gas and electrical mains box" at the house in Newton-le-Willows on 20 December 2022.
It said the woman and teenager's safe escape was only down to "good fortune".
The 36-year-old admitted arson and was sentenced to four years seven months in prison at Liverpool Crown Court.
The force said Buckley, of Lord Street in Southport, "deliberately started a fire in the downstairs of his girlfriend's house before fleeing the property".
A representative said the woman and her daughter were upstairs at the time and "only became aware of the fire after smelling smoke".
"Thankfully, they managed to get out of the house unharmed, but were left shaken by the incident," they added.
Buckley was later arrested and charged, before pleading guilty to a charge of arson.
Speaking after sentencing, Det Ch Insp Allison Woods said to deliberately start a fire in a house, "knowing that there are people inside, is utterly appalling and it's only down to good fortune that the two occupants were unharmed".
"Buckley started a fire in close proximity to a gas and electrical mains box, so it was incredibly reckless and dangerous," she said.
"He not only endangered the lives of the two people inside the house, but also neighbouring properties."
She added that it was pleasing to see him receive "a custodial sentence to reflect the seriousness of his actions".
Source BBC