Breakers Keep Tripping?

I recently started renting a two bedroom house with my buddy. When we moved in half the house didn't have power. The landlord called a electrician and got that fixed but failed to fix the light in my bedroom. A new electrician came to work on my light and they have been here for 3 days, claiming they are rewiring some stuff in the attic. However, since they have been here, we have had problems with breakers tripping due to flipping a light switch.

Most of the outlets in the house are wired to just a couple breakers. One being a 30 amp that trips when the light switch is turned off. The electrician wants to put a 35 amp in its place. Is this safe? Also they fixed my light but now it will not turn off. They say I have a bad light switch. Do these guys know what they are doing or should I be scared that they don't know anything about electrical work?

By Lucas