[Grammar] Make deduction in passive voice

[MaxSava]

Good day, everyone!
I've faced with issue about making deduction in passive voice using modal verbs.
There are some rules for active voice:

MAV (modal auxiliary verb) - can, must, could, might, may, can't
V - infinitive
Ving - verb with -ing
Ved - verb in past participle

Present

subject + MAV + V
subject + MAV + be + Ving


Past
subject + MAV + have + Ved
subject + MAV + have + been + Ving

However, I don't have a clue how to make sentences in passive voice.
For example:

Present
Post might be delivered by postman (subject + MAC + be + Ved) (?)
Traffic-light must being repaired by engineer (i can see that someone is something doing with traffic-light now) (subject + MAC + being + Ved) (?)

Past
Traffic-light might have be broken by hooligans (subject + MAC + have + be + Ved) (?)
My computer might have been used all night (subject + MAC + have + been + Ved) (?)

Could someone correct these sentences or give another good example to understand.
Unfortunately, I can't find any information about this theme in internet. So I appreciate any help.

 

[Tarheel]

The mail is being delivered by the mail carrier.

The traffic light is being repaired by the engineer.

The traffic light might have been broken by hooligans.