Ghosts and apparitions are different then poltergeists. Poltergeists are when the "ghost" is not seen but heard. Poltergeist is from two German words, "poltern" meaning 'to knock' and "geist" meaning 'spirit'. Psycic Echo Bodine defines two different classes as well. Spirits and souls. Ghosts are from people who have either decided not to move on, don't realize their dead or don't know how. A Spirit is someone that has passed over. Sometimes these 'spirits can come back to either help the living or show the dead how to cross over. Moving objects, causing changes in room temperatures and such. Generally poltergeists will start up when either when something in the house changes or is different. Sometimes the stress of one of the occupants of the house can "cause" the experience. Telekinesis is the power to move things with your mind. Sometimes if, under stress, a person may "conjure up" this power without knowing it. This isn't to say that a presence might not be there, I'm just stating that one should consider the effects that are taking place within the home. Have parents been fighting? Did someone lose their job? Always ask questions first. As many as you can think of.
Other times there might just be a presence. Perhaps it is "protecting" someone in the house. Or it could be the simple fact that a past resident didn't like the way you moved the lamp.

You should ask yourself:
1. Have things been increasing?
2. Have they been increasing in intensity?
3. Are they focused around someone in the family?
4. Are they focused around an object?
5. What has changed in the houshold?
6. Are they playful acts or serious?

Ghosts and apparitions are usually timid. They will most likely be seen standing or slowly moving about the house. They are probably older occupants of the house or "stuck with" a certain object either brought into the home or already there. There has never been a case that I'm aware of where a ghost has hurt someone on purpose. If a ghost has appeared, the questions above are good ones to start with. You could also ask yourself if the ghost is searching for something. This is most likely the case. Ghosts`are thought to be spirits that died suddenly or had something to do so badly that they can't leave until it's occomplished. You could either (get up the nerve, first)and try to ask it what it wants, or, by studying it, finding out what it needs. You could also just try telling it, that, he/she has passed away and it is OK to "go".

Flashlight. Um...duh.

Poleroid camera It's important to take as pictures as you can with different kids of camera's. That way if one doesn't work, chances are another will.

Camera. This is THE thing to have. A infrared camers is , of course, much better. I use both a digital and 35 mm.

Video camera. Especially one you can use either on a tripod and in your hands.

Polarized lenses. This may sound stupid, but you never know what you might need to see and these type of lenses offer a "different" view.

Baby powder. This is good for setting near windows that keep "opening" or for seeing if someone is leaving a trail either by foot or "scrapings"

Electrometer. It's EXTREMELY helpful to look for electrical currents that might be in the air.

Digital thermometer. Another thing you'll need is to know if there is a change in the temperature in certain parts of the room. You must take into account for condensation, vapers and such.