How do you know you have a ghost?
If you suspect your home to be haunted, it is either because someone has told you that it was when you moved in or you have started to notice strange occurrences such as sounds, voices, things moving, unexplainable odors and waking up at odd times without reason. If you are experiencing strange phenomena the first thing you need to do is to start a occurrence diary and write down every thing that you notice in as much detail as you can including dates and times when they happen. It is also important to note where they occur, i.e. kitchen, bedroom, bathroom. Start an investigation, talk to people in you neighborhood and see if they have heard anything about your home. Find out who lived there previously and search their names to see if and when they died and if anything out of the ordinary has happened in the home. Speak to your landlord if renting or your realtor about the history of the place. Get a second opinion, have a friend stay over and see if they notice anything strange. Use a tape recorder with a new tape. Load the tape, turn the volume to maximum and push record, once it starts to record it is important that everyone is out of the house, which includes you for the duration of the recording session. This ensures that no one is influencing the tape recorder and allows whatever might be there the opportunity to move around freely. If you have pets this becomes difficult as when you later review the tape you will not know if the sounds are paranormal or pet normal. If you can take them with you for the 30 minutes or the hour depending on the duration of the tape then all the better. Make sure prior to starting tape that all radios, televisions are off, all windows are closed and try to locate the tape recorder in a central location like on your stairs to either the basement or to the second floor or in a hallway. When you review the tape you will have to listen very carefully as you will have a great deal of static on the tape, this is called white noise produced by the value being turned to the max when recording, white noise allows spirits to communicate easier. Listen for whispers or voices and odd sounds.
Ask for a formal investigation by a local paranormal investigation group. Check their background to ensure they are reputable and trustworthy. You if have concerns over media attention or any publicity request a non disclosure agreement first. And remember reputable groups will not charge money to do an investigation.