He might could write his name.

source: 
LAGS
Entry: 
534
Example: 
He might could write his name.
Modal 1: 
might
Modal 2: 
could
Gender: 
Male
Race/Ethnicity: 
White
Age: 
60
Level of Education: 
4th grade (Literate)
Home Community, Town, or State: 
AL (Alpine)
Location Collected: 
AL (Alpine)
Year: 
1973
Relation to Addressee: 
subject to fieldworker
Medium: 
Spoken
Sentence Structure: 
1.0
Status: 
Naturalistic