Purchased a home and prior owner wrote a fake lease to her guest so she could obtain government benefits. The purchase was already over. I gave them all a few weeks to secure housing already, there electric had as already been shut down for unauthorized use. There is no running water making my home a health hazard and causing damage. I didn't find out about all of this prior to me letting them have a few weeks, now they all agreed to vacate but as the time is drawing closer this woman with her bogus lease is going to try and hold me bounded to it. I never wrote her any lease or took any money from any of them. My home is in Pasco county fl. What recourse do I have, please help.

OK, first what makes you think the lease is fake or bogus? If you purchased a home that had a tenant, then you have to honor that tenancy. If you were not aware there was a tenancy, then you can sue the seller.

Under FL law you can give a written vacate notice 15 days prior to rent being due.

But the key here is why you think the lease bogus and what are the terms of the lease.

... prior owner wrote a fake lease ... . The purchase was already over. ...

So you are saying that the prior owner and the tenant signed a post-dated lease after you had closed? As ScottGem notes, apparently the tenant was occupying the premises at the time you closed. If so, the tenant is a tenant-at-will. You can evict after you give a 15-day written notice. Then, when you bring them to court, you will have to prove that the lease is bogus. If you can do that, you should be able to get the court to issue a writ of possession.

You will have to get the owner, to appear in court and say he wrote a bogus lease, or have something in writing, saying the lease is bogus. This is a valid lease, if it is in writing, and it is is signed.

You have obligated to honor the lease.

Now. Most lease, or common rental, require them to pay you. So you can demand payment from the day you purchased property.

You can demand, the security deposit listed in the lease, to be given to you from the seller.

You can also, require the person renting, to have electric and water hooked back up. Failure to do so would be grounds for eviction.

? How is not having the water hooked up, damaging the house? I assume you mean because someone is living there.

Also, assuming you had a valid sales contract on house, (not did anything silly like just writing them a check without contract) the contract should list, if there is a lease or renters in the house. If they lied on the contract, this may be grounds for you to sue for damages of the seller.

...
[assuming the lease cannot be dis-proven] You [are] obligated to honor the lease.

Now. Most lease, or ...

I disagree. In most places, the lease would have had to been recorded prior to the date of closing in order to be enforceable against the purchaser.

Here is the pertinent part of the applicable Florida statute:
"695.01. Conveyances and liens to be recorded
(1) No conveyance, transfer, or mortgage of real property, or of any interest therein, nor any lease for a term of 1 year or longer, shall be good and effectual in law or equity against creditors or subsequent purchasers for a valuable consideration and without notice, unless the same be recorded according to law ..."

Thus, if the supposedly bogus lease is for a period less than a year the tenant may have a case. But I believe the burden of proof would be on the supposed tenant.

"Subsequent purchasers and creditors without notice of a prior unrecorded deed will be protected against such unrecorded conveyance unless the party claiming thereunder can show that such subsequent purchaser or lien creditor acquired his title or lien with notice of such unrecorded conveyance, and the burden of showing such notice is upon the party claiming under such unrecorded conveyance.  Feinberg v. Stearns, 56 Fla. 279, 47 So. 797 (1909) (https://a.next.westlaw.com/Link/Document/FullText?findType=Y&serNum=1908000204&pubNum=0000734&originatingDoc=N1A4AC690F34411E286B1AC049B5CF712&refType=RP&originationContext=notesOfDecisions&contextData=%28sc.Category%29&transitionType=NotesOfDecisionItem);  Hopkins v. O'Brien, 57 Fla. 444, 49 So. 936 (1909) (https://a.next.westlaw.com/Link/Document/FullText?findType=Y&serNum=1909000249&pubNum=0000734&originatingDoc=N1A4AC690F34411E286B1AC049B5CF712&refType=RP&originationContext=notesOfDecisions&contextData=%28sc.Category%29&transitionType=NotesOfDecisionItem). (quoting a proprietary (not freely accessible) site; emphasis added)"

Note that the previous paragraph has to do with the burden of proving notice to the subsequent purchaser. I don't have a citation for you on the burden of proving whether the lease is genuine (i.e.: not post-dated), but I believe that the burden would be the same: on the proponent).