The phrase "in a mishap" is correct and can be used in written English.
It is typically used to describe an accident or unfortunate event that has occurred. Example: "The driver was injured in a mishap on the highway."
During one eventful Christmas vacation, the poor bear finds himself lost in a mishap at the local ski resort.
A painting of God as a naked woman was destroyed in a mishap on the Brooklyn-Oueens Expressway. Brooklyn-Oueens Expressway
On the 54th lap of the 80-lap race, Patrick was involved in a mishap that precipitated the day's fifth yellow flag.
Whenever a military aircraft is involved in a mishap, the Air Force appoints an Accident Investigation Board to determine the cause.
Miltiades, dying of gangrene from a leg wound suffered in a mishap, was fined 50 talents, although the death penalty had been demanded.
John Campbell broke his right elbow and injured his right hand in a mishap in the last race on the Meadowlands card on March 23.
The Baltimore Ravens' top draft pick, Sergio Kindle, hurt his head in a fall in Texas, a mishap that will prevent him from reporting to camp Monday.
Maine was launched from the Navy Yard in 1890, a mishap sent its wooden cradle sliding into the water along with it.
This novel's protagonist loses a hand to a circus lion in India, a mishap that somehow sets him on a course from feckless, womanizing television producer to responsible family man.
"Typically in these situations, a mishap like this results in senior management casualty.
At Alabama, the semiprofessional pursuit of football has resulted in the Bowl Championship Series trophy ending up in shards after a mishap toppled the trophy case.
