Landlord has guest house hooked on to my electricity?

I just moved into a new house with my boyfriend in the beginning of February. When I moved in I wasn't aware of the issue of the guest house on his property being on my electric meter. My boyfriend noticed it while inspecting some things on the property and talked to him, he mentioned if and when he has someone he could give us 1.50 a day. Here's the thing... I never agreed to this and I'm the one that signed the lease. Of course my boyfriend conveniently forgot to tell me until I received an updated lease that the landlord WROTE in the new agreement onto the copy I already signed. Not to mention I've now seen lights on in there every so often, plus who knows what appliances are on in there. We shut the breaker off for his house today because now this is the 2nd night in a row we saw lights on all night---and no notice from my landlord. He called right afterwords of course and said he's had a guest for 4 days and they will be living there permanently. I don't know what my rights are and where to go from here. I told him 1.50 a day is not alright. He said we can split my bill in 3rds. But I do not know how much this youngster will be using. I had just received my 2nd months PGE bill and it is 708kwh vs 350 last month. That's quite a jump for not doing anything substantially different. So sure I can live with splitting it if I can know how much she's using. But right now I don't know and I'm being screwed. Is it even legal to have this on my meter? Not to mention I asked and he wont tell me the details of what appliances/air conditioning (which we do not have)/heating it is. We have gas heat, so i'm uming they might as well, but I could be wrong. I don't know these details and he's not giving them out to me. I feel this is a gross abuse of my rights as a tenant. Am I wrong? Please advise... I don't know what to do or where to go from here.