Lease clause for electrical usages

[Michael Shadow]

Does anyone have any lease clauses that prohibit the use of plug in electric heaters and also I'm looking for a clause that puts a cap on the electric bill.

I have a unit that is on the same meter as the common areas and furnaces so I have to pay the electric on it but the tenants have been abusing their "free" electric so I want to figure out how to put a cap to this. Any help would be fantastic.

Thanks,

-Michael