Usually when we go on an investigation, our clients actually welcome us there. They understand that we're there for a purpose--usually to help them figure out what is going on at their home or business or location. We don't get paid to do this. We really do enjoy just helping out. To be honest, my group does a lot of background before a case to see if it even has merit before sending the team out there. If it seems like somewhere worth our time--even if it's a more subtle haunting at a private residence where the owners just need comfort that they're not nuts--we'll go and check it out. After the prelim, if it's deemed worthy of follow-up, we'll return.
For the first time in my 6-year ghosthunting career, I went on a case where the clients weren't too happy to see us. This was a public/private place and it seems that the first time we were there, the clients made fun of the agents' work, wearing a white sheet like a ghost and making "ghostly" noises. This didn't go over well with the team at all (I wasn't present) and it seems, a resident spirit too. The team was reluctant to return. For good reason, I'd say--although when I saw the pics, found the sheet ghost hilarious.
The second time, they gave us our space, although I'll admit that they were not aware that we were coming (the contact wasn't there and hadn't reminded her colleagues), which was very unnerving. One reason offered was that we had a certain room's lights out and noone likes going there when they're out. They seemed on their best behavior this time compared.
So, here's a lesson learned: Make sure your contact person is going to be present to act as a buffer and liaison and confirm, confirm, confirm. Honestly, many of them had first-hand experiences and I strongly believe there's something unusual going on there--as these particularly clients would have absolutely no reason to lie. However, based upon the quiet of the 2nd investigation and our lack of definitive findings, I'd have to call it inconclusive.