> []{}= "I am found cheating (on the test)."
This sentence is 100% grammatical. If you analyzed it using the grammar of another language, however, it might look as though it were ungrammatical.
, as you stated, is an intransitive verb, but it happens to fall into a group of intransitive verbs that hold the transitive-verb-like characteristics. In particular, these intransitive verbs are used just like transitive verbs in the passive voice with attached to the direct object.
Japanese-learners would need to know that it is far more natural for us to say the sentence above than to say:
> ****
using a real transitive verb in its passive voice form.
This group of intransitive verbs include: []{} = "to be taught"[]{} = "to be blessed with" = "to be told to convey a message or give a present", etc.