Nobody here (or anywhere else) can tell you if you have a ghost/spirit manifesting in your house 🏠 or not. BTW ignore anyone claiming they don't exist; that's just ignorance. No genuine scientist would ever make such a claim as a statement of fact because they know they can't.
To get back to what may or may not be going on in your house 🏠. Seeing stuff is all very well, but your case would be strengthened if other people than yourself have witnessed any phenomena. From personal experience, things to be aware of include:
*Objects moving around, in locked, empty i.e. no people in them.
*Objects moving in a room that you're in, usually out of your sight e.g. behind your back. I'm not talking about being blown or knocked by draughts or vibrations, but very obviously moved, sometimes several feet across the room.
*Objects that seem to "disappear", and then suddenly reappear in a place that you KNOW you have checked previously. I'm not talking about mislaying things but walking 🚶 into a room and seeing the object e.g. on a table when it was not there a few minutes earlier. Obviously this only applies if there are no other people or animals in the house 🏠 at the time.
*Appliances turning on spontaneously, or operating when noone is there them. I've had this happen even when the appliance has been unplugged (no internal battery), so can't blame dodgy electrics.
*Lights switching on or off, including dimmer switches turning from zero to full, so again can't be explained away by electrics.
*Taps turning on again after every time you turn them off, no matter how hard you wrench them shut, and when you know your taps don't normally even drip, and your water pressure is no higher than usual.
*Unexplained noises like footsteps, voices etc. that cannot be explained away by structural sounds, animals within in the walls/loft etc. or sound carried from neighbouring buildings. It's important to rule that out. Again, if someone else other than yourself also hears them, it more reassuring that it isn't just you hearing things.
*And yes, as you mention, seeing things could be significant, but again it's important to rule out any medical or environmental causes, and also check if others have witnessed anything out of the ordinary too.
I would start making a diary and note anything that you think is significant in it. I did so and it helped me in my attempts to make sense of what I've witnessed in the past ten years.
Oh, and look elsewhere for proper advice. This really isn't the best place for it.
Good luck.