Is there any narration stating that if a woman leaves her hair uncovered at home then it does not allow angels to enter the house?
I have not come across a narration as explicit as your question. However there is a weak narration recorded by Imam Muhammad ibn Ishaque, the famous Historian (rahimahullah) which states that once, Jibril (‘alayhis salam) entered the home of Rasulullah (sallallahu’alayhi wasallam) and was visible to Rasulullah (sallallahu’alayhi wasallam).
When Sayyidatuna Khadijah (radiyallahu ‘anha) removed her scarf and exposed her chest, Rasulullah (sallallahu ‘alayhi wa sallam) was then unable to see Jibril (‘alayhis salam) in the home [as he probably left].
This narration is transmitted via a broken chain (munqati’).
(Refer: Siyaru A’lamin Nubala, vol.2 pg.116, Al Isti’ab, vol.4 pg.381 and Usdul Ghabah, vol.7 pg.83/84)
And Allah Ta’ala Knows best.
Answered by: Moulana Suhail Motala
Approved by: Moulana Muhammad Abasoomar
Checked by: Moulana Haroon Abasoomar