She was seen to run into the old house just now.
被看见做某事 有以下两种用法：
be seen to do sth 被看见做了某事,表示动作已经完成
be seen doing sth 指被看见正在做某事,强调动作正在进行
题中是跑进了老房子中,显然是完成动作,用be seen to do sth